CN116794896A

CN116794896A - Multi-pane electrochromic window

Info

Publication number: CN116794896A
Application number: CN202310802337.3A
Authority: CN
Inventors: 罗宾·弗里德曼; 斯里达尔·凯拉萨姆; 拉奥·米尔普里; 罗恩·鲍威尔; 达埃尔亚·什里瓦斯塔瓦
Original assignee: View Inc
Current assignee: View Inc
Priority date: 2010-08-05
Filing date: 2011-07-29
Publication date: 2023-09-22
Also published as: US8665512B2; US10088731B2; US20120033287A1; TW201921074A; TW201715284A; TWI677742B; CN103168269B; TWI582508B; US20210214274A1; US20180373110A1; EP2601555B1; EP2601555A4; US11724964B2; US20150062688A1; EP4210434A1; US20140307301A1; EP3726928B1; US20130021659A1; US8270059B2; EP3726928A3

Abstract

The present application relates to multi-pane electrochromic windows, and in particular describes window units, such as hollow glass units (IGUs) having at least two panes, each pane having an Electrochromic (EC) device thereon. The two optical state devices on each pane of the double pane window unit provide four optical states for the window unit. The described window unit gives the window user more options in how much light can be transmitted through the electrochromic window. Furthermore, by using two or more panes, each with a respective electrochromic device and aligned within the window unit, the visual defect of any individual device can be counteracted by means of this very small likelihood (any visual defect will align well so that it can be seen by the user).

Description

Multi-pane electrochromic window

Information about the divisional application

The application provides a divisional application aiming at the problem of singleness pointed out in the patent divisional application examination process of the application with the application date of 2011, 7, 29, 201710167066.3 and the application name of 'multi-pane electrochromic window'.

The patent division of application No. 201710167066.3 is the division of patent application of application No. 2011, 7 and 29, 201180045191.8, and entitled "multi-pane electrochromic window".

Cross-reference to related applications

The present application claims the benefit of priority from U.S. patent application Ser. No. 12/851,514, filed 8/5/2010, the contents of which are incorporated herein by reference in their entirety.

Technical Field

The present application relates generally to electrochromic devices, and more particularly to electrochromic windows.

Background

Electrochromic is a phenomenon in which a material exhibits an electrochemically mediated change in its optical properties when placed in different electronic states (typically through a change in voltage). The optical properties are typically one or more of color, transmittance, and reflectance. For example, one well-known electrochromic material is tungsten oxide (WO ₃ ). Tungsten oxide is a cathodic electrochromic material in which a coloring transition from transparent to blue occurs due to electrochemical reduction.

While electrochromic has been found in the 60 s of the 20 th century, electrochromic devices unfortunately still have various problems and have not begun to realize their full commercial potential. Electrochromic materials may be incorporated, for example, into windows and mirrors. The color, transmittance, absorbance and/or reflectance of such windows and mirrors may be altered by inducing changes in the electrochromic material. However, because of the problems of conventional electrochromic window electronics, such as high defect rates and low versatility, there is a need for improvements in electrochromic technology, devices, and related methods of making and/or using the same.

Summary of The Invention

Window units, such as Insulated Glass Units (IGUs), having at least two panes, each with an Electrochromic (EC) device thereon are described herein. For example, when a window unit has two panes, each pane has two optical states, so that the window unit can have up to four optical states. The window units described herein allow the window user more options in how much light is transmitted through the electrochromic window, i.e., versatility, i.e., the multi-pane IGU allows grading of light transmission rather than simply "opening or closing" a conventional two-state window. However, an improved two-state window is an embodiment of the present invention. The window described herein allows a user, for example, to adjust the light and heat load entering a room. A second benefit is improved defect rates due to optical defect misalignment. The inventors have found that by using two or more panes, each with a respective electrochromic device and aligned within the window unit, i.e. one pane is located before the other, the visual defect of any individual device can be counteracted by means of this very small likelihood (any visual defect will align well so that it can be seen by the user).

Almost any electrochromic device or device may be used in combination on the panes of a window unit, however low defect electrochromic devices may work very well due to this low likelihood (any visual defects will align so that end users can see). In one embodiment, two-state (e.g., high and low transmittance) all-solid low-defectivity electrochromic devices (located on opposite panes of a two-pane IGU, respectively) are used to create four-state electrochromic windows. In this way, the end user has four options for how much light passes through the window unit, and in fact there is no perceived visual defect for the observer when the electrochromic window is tinted. Other advantages of this technology are described herein.

One embodiment is a window unit comprising: a first substantially transparent substrate and a first electrochromic device disposed thereon; a second substantially transparent substrate and a second electrochromic device disposed thereon; and a sealing barrier between the first and second substantially transparent substrates, the sealing barrier and the first and second substantially transparent substrates together defining an insulated interior region. Embodiments include architectural glass grade substrates and low emissivity coatings may be used. In certain embodiments, at least one of the first and second electrochromic devices faces the interior region, in certain cases both the first and second electrochromic devices face the interior region.

In one embodiment, at least one of the first and second electrochromic devices is a two-state electrochromic device, in some embodiments both the first and second electrochromic devices are two-state electrochromic devices, and the window unit has four optical states. In one embodiment, the first substantially transparent substrate of the window unit when installed will face the outside of a room or building and the second substantially transparent substrate will face the inside of the room or building. In one embodiment, each of the first and second electrochromic devices has a respective high transmission state and low transmission state, and in particular embodiments, the low transmission state of the second electrochromic device has a higher transmission than the low transmission state of the first electrochromic device. In one embodiment, the transmittance of the low transmission state of the first electrochromic device is between about 5% and about 15%, and the transmittance of the high transmission state of the first electrochromic device is between about 75% and about 95%; the transmittance of the low transmission state of the second electrochromic device is between about 20% and about 30%, and the transmittance of the high transmission state of the second electrochromic device is between about 75% and about 95%; for the purposes of this embodiment, the transmissive state of the device includes the transmittance of the substrate upon which it is constructed

Since each device has two optical states (tinting or fading, which correspond to low and high transmittance, respectively), the window units described herein may have four optical states. Each of the four optical states is the product of the transmittance of two electrochromic devices. In one embodiment, the four optical states of the window unit are: i) The total transmittance is between about 60% and about 90%; ii) a total transmittance of between about 15% and about 30%; iii) The total transmittance is between about 5% and about 10%; and iv) a total transmittance of between about 0.1% and about 5%.

In one embodiment, the electrochromic device on the substrate that will face the external environment may be configured to resist environmental degradation better than the electrochromic device on the substrate that faces the interior of the building in which the window unit is installed. In one embodiment, at least one of the first and second electrochromic devices is an all solid state and inorganic device.

Another embodiment is a method of making a window unit, the method comprising: substantially parallel a first substantially transparent substrate having a first electrochromic device disposed thereon and a second substantially transparent substrate having a second electrochromic device disposed thereon; and mounting a sealing barrier between the first and second substantially transparent substrates, the sealing barrier and the first and second substantially transparent substrates together defining an interior region, the interior region being thermally insulated.

These and other features and advantages will be described in more detail below with reference to the accompanying drawings.

Brief Description of Drawings

The following detailed description may be more fully understood when considered in conjunction with the accompanying drawings in which:

fig. 1 depicts a perspective exploded view of a multipane window assembly.

Fig. 2 depicts a cross section of a multipane window assembly.

Fig. 3 is a graph of the solar spectrum and curves representing a four state multipane window assembly.

Fig. 4 is a schematic cross-section of a multipane window assembly.

Fig. 5 depicts a schematic cross-section of an electrochromic device.

Fig. 6A is a schematic cross-section of an electrochromic device in a fade state.

Fig. 6B is a schematic cross-section of the electrochromic device in a colored state.

Fig. 7 is a schematic cross-section of an electrochromic device having ion-conducting, electrically insulating interface regions rather than distinct IC layers.

Fig. 8 is a schematic cross-section of an electrochromic device with particles of an ion-conducting layer causing localized defects within the device.

Fig. 9A is a schematic cross-section of an electrochromic device with particles on a conductive layer prior to deposition of the remainder of the electrochromic stack.

Fig. 9B is a schematic cross-section of the electrochromic device of fig. 6A, wherein a "pop-off" defect is formed during formation of the electrochromic stack.

Fig. 9C is a schematic cross-section of the electrochromic device of fig. 6B, showing an electrical short caused by a pop-off defect once the second conductive layer is deposited.

Fig. 10 depicts an integrated deposition system for fabricating all-solid-state electrochromic devices on architectural glass grade substrates.

Detailed Description

Window units, such as IGUs, having at least two panes, each with an electrochromic device thereon are described herein. For example, when a window unit has two panes, each pane having two optical states, the window unit may have up to four optical states. The window unit described herein gives the window user more options in terms of how much light can pass through the electrochromic window, i.e., the multi-pane IGU concept allows for grading of light transmission rather than simply "opening or closing" a conventional two-state window. A second benefit is the improvement in defect rates due to misaligned optical defects, even for two state windows. The inventors have found that by using two or more panes, each with a respective electrochromic device and aligned within the window unit, i.e. one pane is located before the other, the visual defect of any individual device can be counteracted by means of this very small likelihood (any visual defect will align well so that it can be seen by the user). Further benefits include allowing for lower yields of electrochromic glass to be used, as the defect rate may be higher if two electrochromic panes are combined as described. This may save money from a manufacturing standpoint as well as from a reduced waste stream. Other benefits include enhanced color depth suitable for application to privacy glass, the ability to compensate for shading effects to make the tinting of windows more consistent, and the unique colors that individual devices can have for some degree of color control.

Certain embodiments are described in connection with a low defect rate all-solid-state electrochromic device, although the application is not limited in this respect. Almost any electrochromic device or device may be used in combination, however low defect electrochromic devices may work very well due to this lower likelihood (any visual defects will align so that end users can see).

One of ordinary skill in the art will appreciate that a "two state" electrochromic device refers to a device having a fade state and a color state, each requiring the application of an electrical current. In fact, a two state EC device actually has three states: fade, tint and neutrality. "neutral" describes the "natural" state of the window, with no charge applied to fade or color the window (e.g., fig. 5 shows the EC device in a neutral state, while fig. 6A and 6B show the fade and color states, respectively). For the purposes of the present application, the "state" of an electrochromic device is assumed to be a colored or transparent state obtained by applying an electrical current to the EC device, although the neutral state is the inherent state of the device. For example, a "two-state" multi-pane electrochromic window (e.g., having two panes, each having an electrochromic device, as described herein) would actually be in a (net) state, wherein no current is applied to either or both electrochromic devices. As such, if one electrochromic device is in a colored state and the other electrochromic device is "neutral," then they collectively form an additional optical state of the window unit.

Multi-pane electrochromic window

In the present application, a "window unit" comprises two substantially transparent substrates, e.g. two panes of glass, wherein each substrate is provided with at least one electrochromic device and a spacer is provided between the panes. Since an IGU may comprise more than two glass panes assembled into a unit, and for electrochromic windows in particular may comprise electrical leads for connecting the electrochromic glass to a voltage source, an exchanger, etc., the term "window unit" is used to express a simpler sub-assembly. That is, for the purposes of the present application, the IGU may include more components than the window unit. The most basic component of a window unit is two substrates, each with an electrochromic device thereon, with a sealing barrier between the two substrates, which is aligned with the two substrates.

The inventors have found that by using two or more electrochromic panes in a window unit, the visual defect of any single device can be counteracted by virtue of this very small likelihood (any visual defect will be well aligned so that it can be seen by the user). Almost any electrochromic device or device may be used in combination, however, the low defect electrochromic devices described above work particularly well. In one embodiment, all-solid low-defect-rate electrochromic devices (one on each of the two panes of an electrochromic window) are opposite each other in an IGU. Thus, when, for example, both electrochromic panes are colored, there is little visual defect detectable to the observer.

One embodiment is a window unit comprising: a first substantially transparent substrate and a first electrochromic device disposed thereon; a second substantially transparent substrate and a second electrochromic device disposed thereon; and a sealing barrier between the first and second substantially transparent substrates, the sealing barrier defining an insulated interior region with the first and second substantially transparent substrates.

Fig. 1 depicts a window unit 100 having a first substantially transparent substrate 105, a spacer 110, and a second substantially transparent substrate 115. Electrochromic devices (not shown) are fabricated on both substrate 105 and substrate 115. When the three components are combined, with the spacer 110 sandwiched between the substrates 105 and 115 and aligned with the substrates 105 and 115, the window unit 100 is formed. The window unit 100 has an interior space defined by the surface of the substrate in contact with the partition and the interior surface of the partition, which are connected. The barrier 110 is typically a hermetic barrier, i.e., includes a barrier sheet and a seal between the barrier sheet and each substrate, wherein the barrier sheet and the seal abut to hermetically seal the interior region, thereby protecting the interior from moisture and the like. As a matter of convention, for the two pane window units described herein, the four visible surfaces of the substrate are indicated by numerals. The surface 1 is the surface of a substrate which is located, for example, outside a room or building, where a wall-mounted window has such a window unit. Stylized sun is included to indicate that the surface 1 is to be exposed to, for example, an external environment. The surface 2 is the other surface of the substrate which is located in the interior space of the window unit. The surface 3 is the surface of the second substrate that is located in the interior space of the window unit. The surface 4 is the other surface of the second substrate, which is located outside the interior space of the window unit but inside e.g. the room or building described above. The practice does not make sure that the window unit described herein is fully used in the interior space of a building, however, it is of particular advantage to use the window unit on the exterior wall of a building due to its optical and insulating properties.

"substantially transparent substrates" include those described herein in connection with solid state electrochromic devices. I.e. it is substantially rigid, such as glass or plastic glass. The substrates of the window units need not be made of the same material, e.g. one substrate may be plastic and the other may be glass. In another example, one substrate may be thinner than another substrate, for example, a substrate that will face the interior of a building (i.e., a substrate that is not exposed to the environment) may be thinner than a substrate that will face the exterior of a building. In one embodiment, an electrochromic device that is close to the outside environment of, for example, a building, is better resistant to environmental degradation than a second electrochromic device that is close to the inside of the building. In one embodiment, at least one of the first and second substantially transparent substrates comprises architectural glass. In another embodiment, at least one of the first and second substantially transparent substrates further comprises a low emissivity coating. In another embodiment, at least one of the first and second substantially transparent substrates further comprises a UV and/or Infrared (IR) absorber, and/or a UV and/or IR reflective layer. In one embodiment, the UV and/or IR reflective and/or absorber layer is located on surface 1, in another embodiment on surface 2, in yet another embodiment on surface 3, and in another embodiment on surface 4. In these embodiments, it is contemplated that such a layer or coating may be in direct contact with the surface of the pane and/or be located, for example, on top of the EC stack on the surface of the substrate, thus "on" the surface means on or in connection with the surface. One embodiment is any window unit described herein wherein one or more of the EC devices have UV and/or IR absorbers and/or UV and/or IR reflective layers thereon.

In one embodiment, at least one of the transparent conductive oxides of one of the electrochromic devices is configured so that it (which is a component of the electrochromic device) can be heated by applying an electrical current independent of the operation of the electrochromic device. This is useful for a number of reasons, such as preheating the EC device prior to conversion and/or creating a thermal barrier to improve heat loss inside the building. As such, one embodiment is a window unit as described herein wherein one of the transparent conductive oxides of one of the electrochromic devices is configured so that it can be heated (which is a component of the electrochromic device) by applying an electrical current independent of the operation of the electrochromic device. One embodiment is a two pane electrochromic window as described herein, with EC devices on the faces of each pane at the interior region (surfaces 2 and 3), and the transparent conductive oxide of the EC device on surface 3 configured to heat it by application of electricity, independent of the operation of the EC device. Another embodiment is a two pane electrochromic window unit as described in connection with fig. 1, wherein each of the two electrochromic devices has a TCO (which is a component of the device) configured for heating independent of the operation of the device. This configuration is particularly useful in cold climates where the external pane is cooler, the TCO (which is a component of the device) may be heated prior to, for example, transitioning the device, so that the device transitions by means of preheating. For example, the TCO of the device on the interior pane may also be heated to create a thermal barrier that may retain heat within the building.

The electrochromic devices on each transparent substrate need not be of the same type. That is, one may be, for example, an all-inorganic solid state while the other includes an organic-based electrochromic material. In one embodiment, both electrochromic devices are all solid state and inorganic, and in another embodiment, both electrochromic devices are also low defect rate devices, such as low defect rate all solid state electrochromic devices as described herein. By aligning two such electrochromic devices as described, a window unit with little visible defects in tinting can be made.

The electrochromic devices need not be opposite each other within the interior region of the window unit (e.g., on surfaces 2 and 3), but in one embodiment are opposite each other. This configuration is desirable because both electrochromic devices are in the interior area of the window unit and are protected from the outside environment. It is also desirable that the electrochromic device extends over substantially the entire viewable area of the transparent substrate upon which it is positioned.

Fig. 2 depicts a cross section of a window unit 200 that includes an architectural glass pane 205 with an electrochromic device 210 disposed thereon. The window unit 200 further includes a second architectural glass pane 215 having an electrochromic device 220 disposed thereon. The interior regions of the window units 200 of the devices 210 and 220 are opposite each other. The sealing spacer 225 seals the window unit and in this example overlaps the electrochromic device. An electrical connection (not shown) may also pass through or contact the spacer 225. The spacer 225 may be one piece or made of multiple components (e.g., a rigid or semi-rigid spacer and one or more adhesives and/or sealing elements). In one example, separator 225 includes a spacer (e.g., a metal spacer), a seal (sometimes referred to as a primary seal) that seals the area of the spacer in contact with each pane, and a seal (sometimes referred to as a secondary seal, e.g., a sealing adhesive) between the panes around the perimeter of the spacer. The separator 225 is simplified for ease of description of fig. 2.

As noted above, because electrochromic window units are subjected to higher temperatures (due to the absorption of radiant energy by the electrochromic devices on the glass), stronger separators and sealants are needed relative to those used by conventional IGUs. The sealing barrier 225 is disposed in the surrounding areas of the first and second substantially transparent substrates and does not substantially obscure the viewable area of the window unit (again, e.g., as depicted in fig. 1). In one embodiment, the sealing barrier hermetically seals the interior region. The interior region of the window unit 200 is typically (but not necessarily) filled with an inert gas, such as argon or nitrogen. In one embodiment, the interior space is substantially free of liquid. In one embodiment, the interior space is filled with an inert gas and substantially free of liquid. In one embodiment, the interior space is substantially dry, i.e., has a moisture content of less than about 0.1ppm. In another embodiment, the interior space will require at least about-40 ℃ to the dew point (condensation of water vapor from the interior space), and in another embodiment the interior space will require at least about-70 ℃.

The pane 205 of the window unit 200 is depicted facing the outside environment (e.g., as illustrated by solar rays), while the pane 215 faces the interior of a building (e.g., an office building) as illustrated by the outline of a person working. In certain embodiments, it is desirable to manufacture window units having different electrochromic states for the interior and exterior electrochromic devices, i.e., the device proximate the interior environment and the device proximate the exterior environment, in terms of transmittance. In one embodiment, at least one of the first and second electrochromic devices is a two state electrochromic device. In another embodiment, the first and second electrochromic devices are both two-state electrochromic devices, so the window unit has four optical states. In one embodiment, the first substantially transparent substrate of such a window unit when installed faces the outside of a room or building, the second substantially transparent substrate will face the inside of the room or building, and each of the first and second electrochromic devices has a respective high transmission state and low transmission state, and the transmittance of the low transmission state of the second electrochromic device is higher than the transmittance of the low transmission state of the first electrochromic device. Herein, the "transmissive state of the device" refers to the transmittance of the device itself or a combination of the device and the substrate upon which it is deposited. That is, for example, most substrates have some inherent absorption characteristics, e.g., float glass itself typically has a transmission of about 92%.

One reason for making the low transmission state of the first (outer) device lower than the low transmission state of the second (inner) device is that devices close to the outer can block more light (and therefore heat) from transmitting, thus reducing the requirements on the inner devices. For example, since the external device filters a large portion of the solar spectrum, the internal device may be protected from degradation (as compared to a device without such protection). Thus, the EC device on the inner pane, for example, need not be as strong, e.g., all solid and inorganic.

Another advantage of multiple panes, e.g., a two pane window with devices each, is that none of the devices require a strictly lower transmittance (e.g., less than 10%) because the net transmittance through the window unit is the product of the two devices' transmittance. Another advantage is that if the window unit is only and relies on a single electrochromic device, each device will be thinner than the single electrochromic device. Thinner devices mean less material is used, which saves manufacturing costs. Thinner devices also mean faster reaction times during the transition, which can save money by, for example, using less electrical energy and controlling the thermal load to enter the room faster, and make windows more attractive to the end user.

Another advantage of a window having more than one electrochromic pane (e.g., two electrochromic panes, as described in connection with fig. 2) is that the charge for powering the panes can be shared between the panes by a controller (e.g., a suitably programmed computer that includes program instructions for performing charge sharing operations between the two electrochromic panes). Thus, one embodiment is a method of operating a multipane electrochromic window comprising sharing an electrical charge between panes of the multipane electrochromic window.

Yet another advantage of a multipane electrochromic window unit relates to the shading effect. When electrochromic windows change from dark to light, or from light to dark, there is typically a transition period, i.e., the transition is not instantaneous. During the transition, there may be visual anomalies, and/or a transition inconsistency across the viewable surface of the window. For example, in a window where the bus bars provide voltage to the electrochromic device, the bus bars may be disposed on opposite sides (e.g., the top and bottom of the device in the IGU). When such a window is changed, for example from bright to dark, the device darkens according to the change in sheet resistance of the device surface. Thus, the edges darken first, and there is a darkened front (flush or no) that diverges outward from each busbar and moves toward the center of the window. The two fronts meet somewhere in the viewable area and eventually the window completes the transition to the dark state. This detracts from the appearance of the window during the transition. However, for example, with a dual pane electrochromic window having electrochromic devices on each pane, the transition can be complemented and the shading effect minimized. For example, if the busbar of one pane is at the top and bottom of the pane and the busbar of the other pane is on both sides of the pane, i.e. orthogonal to the busbar of the first pane, the transition will complement for more area to darken faster, for example when both devices are darkened. In another example, the bus bars of the first pane are arranged so that the first pane darkens/lightens from the center outwards and the bus bars of the second pane are arranged so that the second pane darkens/lightens from the periphery inwards. In this way, the shading effect of each pane is complementary to the shading effect of the other pane, thereby minimizing the overall shading effect seen by the user.

In one embodiment, two or more electrochromic devices (each having two optical states) of a multi-pane electrochromic window are connected (simultaneously actuated or not) so that they are fully open or fully closed. Thus, when in the absence or substantially absence, visual defects are discernible to the naked eye. That is, its high transmittance state is used with a low transmittance state, both high or both low. This is a two state multi-pane electrochromic window. As mentioned above, there is of course also a neutral state in which no current is applied, in connection with each two-state device, and a two-state window is intended to include a state in which no current is applied to one or both panes.

Another embodiment is a four state multi-pane electrochromic window. In one embodiment, the four-state window has two panes, each pane having a two-state electrochromic device. Because each pane has a high transmittance state and a low transmittance state, when combined, an electrochromic window comprising electrochromic panes has four possible states. An example of such a two pane window unit device transmittance configuration is shown in table 1. In this example, each of the inner and outer window panes has two states, an open and a closed, corresponding to a low transmittance state and a high transmittance state, respectively. For example, the inner pane has a high transmittance of 80% and a low transmittance of 20%, while the outer pane has a high transmittance of 80% and a low transmittance of 10%. Since the device of each pane has two optical states, a high transmission state and a low transmission state, and both can be combined in all possible ways, the window unit has four optical states.

As summarized in table 1, state 1 occurs, for example, when the electrochromic device of the inner pane is off and the electrochromic device of the outer pane is off. Since the transmittance of both devices is 80%, the net transmittance through both panes is 64% (i.e., 80% of 80%) when both electrochromic devices are off. Thus, when the window as a whole is not electrically dissipative, the pane generally allows 64% of the ambient light to pass through the window unit. State 2 occurs when the inner pane's device is open but the outer pane's device is closed, thus allowing a net transmission of 16% (20% of 80%) through. When the inner pane's means is closed but the outer pane's means is open, state 3 occurs, thus allowing a net transmission of 8% (80% of 10%) through. When the inner pane's means is open and the outer pane's means is open, state 4 occurs, thus allowing a net transmission of 2% (20% of 10%) through. Thus, a four state electrochromic window allows a user to select from four optical states, such as selecting a high transmission when one wants more light to enter the room, such as selecting a very low transmission when one wants the room to darken, such as during a slide presentation. In state 1, there is no visible optical defect, since none of the electrochromic devices is in a dark state. In state 4, there are no visible optical defects, since the probability of alignment of the two defects (each present on one device) is very small, so the opacity of one device must block the optical defects of the other pane.

The user may also select two intermediate states of transmissivity which may provide more flexibility than a simple two state, i.e. bright or dark/open or close electrochromic windows. The optical defect is also unlikely to be observed in these two intermediate transmittance states because, although the means of one pane is turned off, the pane that is activated only blocks 80% or 90% of the light transmission that would pass through the pane (in this example). The visibility of optical defects is proportional to the transmission and background of the window. When a very dark window is mounted in front of a very bright background, i.e. the aperture is directly opposite the sun at 1% t _vis The visual defects are most evident in windows. Since the window is not as dark as, for example, state 4 (where 98% of the light is blocked), any optical defects present are less noticeable because they are not as high as the contrast ratio when the electrochromic device is much darker. This is another advantage of configuring the device to have a higher transmissivity as the inner pane because the contrast between the optical defect and the darkened portion of the device is lower, e.g., state 2 when the inner pane blocks 80% of the light is compared to state 3 when the outer pane blocks 90% of the light. During state 3, when When the outer pane blocks 90% of the light, there is an additional inner pane through which the user will observe any contrast. The inner pane may have certain reflectivity and or refractive properties that will make it less likely that optical defects in the outer pane will be observed in state 3. However, low defect rate windows also reduce the observable optical defects.

Fig. 3 is a graphical representation of the approximate solar spectrum (solid line). It can be seen that a large amount of near infrared radiation passes through standard windows, and thus unwanted heating occurs inside buildings with such windows. Also depicted in fig. 3 are transmittance curves for the four optical states as described in connection with table 1, these 4 curves (dashed lines) being labeled 1, 2, 3 and 4, respectively. For example, the maximum value of curve 1 is about 550 nanometers in the visible range, which corresponds to a net transmittance of 64% (state 1), i.e., the level of light that the user would actually observe through the window unit. State 1 allows a large amount of light to pass through the window unit, and also allows a large portion of the near infrared spectrum (which allows passive solar heating if desired) to pass through the window unit. This compares to typical low-E coating formation, although low-E coatings allow a significant amount of visible light to pass through, block most of the near infrared spectrum and do not allow passive solar heating in winter (although the embodiments described herein include low-E coatings). States 2-4 allow much less light to enter and the near infrared spectrum, thus greatly reducing unwanted internal heating, e.g., saving energy for reducing building temperature during hot summer months. Thus, it is desirable for electrochromic windows to have more than two states, with intermediate states allowing for light adjustment and/or thermal control as desired. The electrochromic window units described herein can also reduce a significant amount of the ultraviolet spectrum from entering the interior of a building.

Thus, one embodiment is a window unit wherein the transmittance of the low transmission state of the first (external) electrochromic device is between about 5% and about 15%, and the transmittance of the high transmission state of the first electrochromic device is between about 75% and about 95%; and the transmittance of the low transmission state of the second (inner) electrochromic device is between about 20% and about 30%, and the transmittance of the high transmission state of the second electrochromic device is between about 75% and about 95%. In one embodiment, the window unit has four optical states as the product of the high transmittance and low transmittance values of the two devices: i) The total (net) transmittance is between about 60% and about 90%; ii) a total transmittance of between about 15% and about 30%; iii) The total transmittance is between about 5% and about 10%; and iv) a total transmittance of between about 0.1% and about 5%.

In one embodiment, the first and second substantially transparent substrates are each architectural glass. By using two low defect rate electrochromic devices, even on a construction grade glass substrate, aligned as in fig. 1 and 2, for example, the window unit is substantially free of visual defects. One embodiment is an IGU constructed from the window units described herein. Architectural glass window units are particularly desirable because of the high demand for controlling energy costs for large buildings.

One embodiment is an IGU comprising: a first pane of architectural glass comprising a first electrochromic device disposed thereon; a second pane of architectural glass comprising a second electrochromic device disposed thereon; a sealing barrier between the first and second panes, the sealing barrier and the first and second panes together defining an interior region between the first and second panes; and an inert gas or vacuum within the interior region; wherein the first electrochromic device and the second electrochromic device are both in the interior region. One or both of the panes in the IGU may have a low-E coating. In one embodiment, both the first electrochromic device and the second electrochromic device are entirely solid state and inorganic. In another embodiment, the first and second electrochromic devices are both two-state electrochromic devices, and the IGU has four optical states. In one embodiment, the four optical states are: i) The total transmittance is between about 60% and about 90%; ii) a total transmittance of between about 15% and about 30%; iii) The total transmittance is between about 5% and about 10%; and iv) a total transmittance of between about 0.1% and about 5%. In one embodiment, the IGU is free of visual defects.

The complementary method is consistent with the described device embodiments. One embodiment is a method of grading the transmittance of an electrochromic window comprising: (i) Combining a first electrochromic window pane and a second electrochromic window pane into an IGU, wherein the first and second electrochromic panes each have two optical states, namely high transmittance and low transmittance; and (ii) operating two electrochromic windows in four modes, comprising: 1. both panes are in a high transmittance state; 2. the first electrochromic window pane is in its low transmittance state and the second electrochromic window pane is in its high transmittance state; 3. the first electrochromic window pane is in its high transmittance state and the second electrochromic window pane is in its low transmittance state; and 4. Both panes are in a low transmittance state. In one embodiment, the first electrochromic window pane is an interior pane of an electrochromic window, the second electrochromic window pane is an exterior pane of the electrochromic window, and the low transmittance of the first electrochromic pane is greater than the low transmittance of the second electrochromic window pane.

One embodiment is a multi-pane electrochromic window in which each pane includes electrochromic devices and in which at least one of the electrochromic devices has intermediate state properties, i.e., a variable tint state between final states (i.e., fully dark and fully light states) is achieved. The value of this embodiment is a broader dynamic range of states rather than a "digital" state as described, for example, in connection with table 1. In one embodiment, the window unit has two panes, and in another embodiment, the window unit has three panes.

Another aspect of the invention is a multi-pane EC window unit having one or more EC devices, each EC device located on a separate pane of the window unit, the window unit including the pane having no EC device but including at least one heatable transparent conductive oxide. In one embodiment, the "TCO only" pane of the window unit may also include UV and/or IR absorbing and/or reflecting coatings, low-E coatings, and the like. As described herein, the transparent conductive oxide can be heated by, for example, a bus bar that provides electrical energy to pass current through the transparent conductive oxide. In one embodiment, the window unit has three panes, two of which have respective EC devices, and the third pane has a heatable transparent conductive oxide. In one embodiment, the order of panes is a first pane with an EC device, a second pane with an EC device, then a third pane with a heatable TCO. In one embodiment, the first and second panes, each having an EC device, may be configured such that the EC devices are located on, for example, surfaces 2 and 3, or, for example, surfaces 2 and 4 (with respect to the surfaces in fig. 1); in combination with TCO on a third pane facing, for example, surface 4. That is, the second EC pane and TCO-only pane of the second interior region, along with the separator described herein, wherein the EC device of the second pane and the TCO of the TCO-only pane are in the second interior region. In one example, the third pane is the innermost pane of the building interior when the window unit is installed. In another example, a third pane is positioned between the first and second panes, each pane having an EC device thereon.

Fig. 4 illustrates two configurations of a three pane window unit having two EC panes (each with an EC device) and one third pane (with a heatable TCO). Configuration 400a shows a first pane (as described herein) 405 with an EC device 410 (as described herein). A spacer (as described herein) 425a separates and seals the first interior region between pane 405 and pane 415. Pane 415 has EC device 420 thereon. The second separator 425b separates and seals the second interior region between pane 415 and third pane 435, with the third pane 435 having a heatable TCO,430 thereon. In configuration 400b, the EC device 420 is within the second interior space opposite the TCO 430 and facing the TCO 430. One of ordinary skill in the art will appreciate that the EC device or TCO may be located on the face of the pane exposed to ambient conditions, rather than the interior region, without departing from the scope of the invention.

Another embodiment is the window unit described in connection with fig. 4, but each of 410, 420, and 430 is an electrochromic device, as described herein. In one embodiment, devices 410 and 430 are all solid state and inorganic, and device 420 is an organic-based EC device on a glass substrate or polymeric film. In another embodiment, all three EC devices are all solid state and inorganic.

Another embodiment is the window unit described in connection with fig. 4, but 420 and 415 are replaced with UV and/or IR absorbers and/or reflective films, and two external panes are EC device panes as described herein. For example, one embodiment is a window unit having two EC panes and one or more UV and/or IR absorbers and/or reflective films disposed in the interior space. The configuration in fig. 4 (with two spacers) is one way of performing the present embodiment.

One embodiment is a window unit as described herein, wherein the transparent conductive oxide of at least one of the EC devices is heatable, e.g., by applying electricity to resistively heat the TCO. One embodiment is a two pane electrochromic window as described herein, wherein each pane has an EC device on a face of the interior region (such as faces 2 and 3 described in connection with fig. 1), and at least one transparent conductive oxide of one of the EC devices is configured to heat it by application of electricity, the heating being independent of operation of the EC device. When installed in a building, one pane is exposed to the outside and the other pane is exposed to the inside, the heatable TCO may be located on the face facing the inside or outside of the building. As described above, there are associated insulation and EC transition benefits when two heatable TCOs are used.

Another aspect is a multipane EC window unit having two panes (substrates), wherein a first substrate has electrochromic devices and a second transparent substrate does not, but the second substrate comprises a transparent conductive oxide (e.g., indium tin oxide) that can be heated, such as by applying electricity using bus bars. In one example, the window unit is configured similar to the window unit described in fig. 2, however, for example 220 is not an EC device, but rather a heatable TCO. Thus, one embodiment is a window unit comprising: a first substantially transparent substrate and an electrochromic device disposed thereon; a second substantially transparent substrate and a heatable transparent conductive oxide thereon; and a sealing barrier between the first and second substantially transparent substrates, the sealing barrier defining an insulated interior region with the first and second substantially transparent substrates. In one embodiment, both the electrochromic device and the heatable transparent conductive oxide are within the interior region. In one embodiment, the second substantially transparent substrate comprises an infrared reflective and/or infrared absorbing coating. In one embodiment, the electrochromic device is all solid state and inorganic.

Advantages of the above configuration include: 1) improved insulation properties (U-value), 2) higher flexibility of the material used for the suspended film (i.e. organic based) due to the fact that some UV/IR filtering will occur by, for example, a first stronger inorganic means (which will allow the use of a less stronger organic means in the interior area of the window unit), and 3) the use of transparent conductive oxide as a heating element for e.g. insulating heat during EC transitions at low temperature conditions and/or providing assistance to prevent heat loss through the window at night and/or during cooler weather.

Another embodiment is a method of changing between a plurality of optical states within a window unit, comprising: (i) Changing the optical state of a first electrochromic device of a first substantially transparent substrate without changing the optical state of a second electrochromic device on a second substantially transparent substrate, wherein the window unit comprises first and second substantially transparent substrates connected by a sealing barrier that defines an interior region with the first and second substantially transparent substrates; and (ii) changing the optical state of the second electrochromic device without changing the optical state of the first electrochromic device. The method may further comprise changing the optical state of the second electrochromic device while changing the optical state of the first electrochromic device. By combining these actions, the window unit provides a plurality of optical states to the end user.

Another embodiment is a method of making a window unit, the method comprising: substantially parallel a first substantially transparent substrate having a first electrochromic device disposed thereon and a second substantially transparent substrate having a second electrochromic device disposed thereon; and mounting a sealing barrier between the first and second substantially transparent substrates, the sealing barrier and the first and second substantially transparent substrates together defining an interior region that is thermally insulated. In one embodiment, at least one of the first and second substantially transparent substrates comprises architectural glass. In one embodiment, at least one of the first and second substantially transparent substrates further comprises a low emissivity coating. In another embodiment, both the first and second electrochromic devices face the interior region. In one embodiment, at least one of the first and second electrochromic devices is a two-state electrochromic device, in some embodiments, both the first and second electrochromic devices are two-state electrochromic devices, and the window unit has four optical states. In one embodiment, at least one of the first and second electrochromic devices is an all solid state and inorganic device. In one embodiment, the transmittance of the low transmission state of the first electrochromic device is between about 5% and about 15%, and the transmittance of the high transmission state of the first electrochromic device is between about 75% and about 95%; the transmittance of the low transmission state of the second electrochromic device is between about 20% and about 30%, and the transmittance of the high transmission state of the second electrochromic device is between about 75% and about 95%. In one embodiment, the four optical states are: i) The total transmittance is between about 60% and about 90%; ii) a total transmittance of between about 15% and about 30%; iii) The total transmittance is between about 5% and about 10%; and iv) a total transmittance of between about 0.1% and about 5%. The sealing barrier hermetically seals the interior region, and the interior region may contain an inert gas or vacuum and/or be substantially free of liquid. In one embodiment, the window unit is free of visual defects. In another embodiment, the window unit is an IGU.

Another embodiment is a method of manufacturing an IGU, the method comprising: disposing a first pane of architectural glass and a second pane of architectural glass in a substantially parallel arrangement, wherein the first pane includes a first electrochromic device disposed thereon and the second pane includes a second electrochromic device disposed thereon; and installing a sealing barrier between the first and second panes, the sealing barrier together with the first and second panes defining an interior region between the first and second panes, the interior region being thermally insulated. Filling the interior region with an inert gas; wherein the first electrochromic device and the second electrochromic device are within the interior region and are all solid state and inorganic. In one embodiment, at least one of the first and second panes further comprises a low emissivity coating. In another embodiment, the first and second electrochromic devices are both two-state electrochromic devices, and the IGU has four optical states. In one embodiment, the four optical states are: i) The total transmittance is between about 60% and about 90%; ii) a total transmittance of between about 15% and about 30%; iii) The total transmittance is between about 5% and about 10%; and iv) a total transmittance of between about 0.1% and about 5%. In one embodiment, the IGU is free of visual defects.

As mentioned above, the present invention will be applicable to virtually any electrochromic device. In some embodiments, more than one type of electrochromic device is used in the window unit, for example, more robust electrochromic devices are used on the outer pane and less robust devices are used on the inner pane. All solid state and inorganic electrochromic devices are particularly suitable for use in the present invention. Thus, for the context and with respect to embodiments including such devices, electrochromic device technology will be described below in connection with two types of all-solid-state and inorganic electrochromic devices, particularly low defect rate all-solid-state and inorganic electrochromic devices. These devices are particularly suitable for the embodiments described herein due to their low defect rates and robustness. An embodiment of the invention is any described embodiment comprising one or more electrochromic devices, wherein the one or more electrochromic devices are selected from the first and second types described below. In certain embodiments, one or more electrochromic devices are low defect rate devices, wherein the defect rate level is defined below. The first type is a device with layers of different materials in the electrochromic stack, and the second type is a device with ion-conductive electrically insulating interface regions that function as different ion-conductive layers in the first type.

Low defect rate solid state electrochromic device with different layers

Fig. 5 depicts a schematic cross-section of an electrochromic device 500. Electrochromic device 500 includes a substrate 502, a Conductive Layer (CL) 504, an electrochromic layer (EC) 506, an ion conductive layer (IC) 508, a counter electrode layer (CE) 510, and a Conductive Layer (CL) 514. Layers 504, 506, 508, 510, and 514 are collectively referred to as electrochromic stack 520. A voltage supply 516 operable to apply a potential across the electrochromic stack 520 transitions the electrochromic device from, for example, a fade state to a color state (described). The order of the layers relative to the substrate may be reversed.

Electrochromic devices with the different layers described can be fabricated as all-solid-state inorganic devices with low defect rates. U.S. patent application Ser. No. 12/645,111, entitled "manufacturing Low Defect Rate electrochromic device" Fabrication of Low-Defectivity Electrochromic Devices, filed on month 12, 22, 2009, and U.S. patent application Ser. No. 12/645,159, entitled "electrochromic device" Electrochromic Devices, entitled "electrochromic device" and methods of manufacturing such an all solid state electrochromic device, filed on month 12, 22, 2009, are described in greater detail herein for all purposes.

It should be understood that the transition between the fade state and the color state referred to is non-limiting and that only one example of an executable electrochromic transition is suggested in many examples. Whenever a fade-to-color transition is mentioned, the corresponding device or process includes other optical state transitions, such as non-reflective, transparent-opaque, etc., unless otherwise specified herein. Further, the term "fade" refers to an optically neutral state, such as uncolored, transparent or translucent. Further, unless otherwise indicated herein, the "color" of an electrochromic transition is not limited to any particular wavelength or range of wavelengths. As will be appreciated by those skilled in the art, the selection of the appropriate electrochromic material and counter electrode material determines the relevant optical transition.

In certain embodiments, the electrochromic device reversibly cycles between a fade state and a color state. In the fade state, an electrical potential is applied to electrochromic stack 520 such that the available ions in the stack that can cause electrochromic material 506 to change to the colored state are present primarily in counter electrode 510. When the potential applied to the electrochromic stack is reversed, ions are transported through the ion conducting layer 508 to the electrochromic material 506 and put the material into a colored state. The transition from the fade to the colored state, and from the colored to the fade state, will be described in more detail below.

In certain embodiments, all of the materials comprising electrochromic stack 520 are inorganic, solid (i.e., are solid), or both inorganic and solid. Since organic materials are susceptible to degradation over time, inorganic materials have the advantage of reliable electrochromic stacks that can function for long periods of time. Solid materials also have the advantage of not having containment and leakage problems, unlike liquid materials which often do. Each layer in the electrochromic device will be discussed in detail below. It should be understood that any one or more of the layers in the stack may contain a certain amount of organic material, but in many implementations, one or more of the layers contains no or little organic material. The same is true for small amounts of liquid present in one or more layers. It will also be appreciated that the solid material may be deposited or formed by a process using a liquid component, such as some processes using sol-gel or chemical vapor deposition.

Referring again to fig. 5, the voltage source 516 is typically a low voltage power source and may be configured to work in conjunction with radiation and other environmental sensors. The voltage power supply 516 may also be configured to interface with an energy management system, such as a computer system that controls the electrochromic device based on some factors (e.g., date, time of day, and measured environmental conditions). Such energy management systems in combination with large area electrochromic devices (i.e., electrochromic windows) can greatly reduce the energy consumption of the building. As is apparent from the description of the multi-pane electrochromic window described herein, certain energy is saved for heating and cooling.

Any material having suitable optical, electrical, thermal, and mechanical properties may be used as the substrate 502. Such substrates include, for example, glass, plastic, and specular materials. Suitable plastic substrates include, for example, acrylic, polystyrene, polycarbonate, allyl diglycol carbonate, SAN (styrene acrylonitrile copolymer), poly 4-methyl-1-pentene, polyesters, polyamides, and the like. If a plastic substrate is used, it is preferably protected from abrasion using a hard coating such as a diamond-like protective coating, a silica/silicone abrasion resistant coating, or the like (e.g., as is well known in the plexiglas art). Suitable glasses include transparent or colored soda lime glass, including soda float glass. The glass may be tempered glass or non-tempered glass. In some embodiments of electrochromic device 500 in which glass (e.g., soda lime glass) is used as substrate 502, there is a sodium diffusion barrier (not shown) between substrate 502 and conductive layer 504 to prevent sodium ions from diffusing from the glass into conductive layer 504.

In some embodiments, the optical transmittance (i.e., the ratio of transmitted radiation or spectrum to incident radiation or spectrum) or "transmittance" of the substrate 502 is about 40% to 95%, such as about 90% -92%. The substrate may have any thickness as long as there are suitable mechanical properties to support the electrochromic stack 520. Although substrate 502 can have nearly any suitable thickness, in some embodiments it is about 0.01 millimeters to 10 millimeters thick, preferably about 3 millimeters to 9 millimeters thick. The multi-pane window units described herein may have individual panes of different thickness. In one embodiment, the interior (near the building interior) pane is thinner than the exterior (near the outside environment) pane, which must resist more extreme exposure.

In some embodiments, the substrate is architectural glass. Architectural glass is glass used as a building material. Architectural glass is commonly used in commercial buildings, but may also be used in residential buildings, and typically (although not necessarily) separates an indoor environment from an outdoor environment. In certain embodiments, the architectural glass is at least 20 inches by 20 inches, and may be much larger, such as about 72 inches by 120 inches. Architectural glass is typically at least about 2 millimeters thick. Architectural glass less than about 3.2 millimeters thick cannot be tempered. In some embodiments where architectural glass is used as the substrate, the substrate may be tempered even after the electrochromic stack has been fabricated on the substrate. In some architectural glass as the substrate embodiments, the substrate is soda lime glass from a tin float process line. For neutral substrates, the transmittance of the architectural glass substrate over the visible spectrum (i.e., the total transmittance of the entire visible spectrum) is typically greater than 80%, whereas for tinted substrates the transmittance may be lower. Preferably, the transmittance of the entire visible spectrum of the substrate is at least about 90% (e.g., about 90-92%). The visible spectrum is the spectrum that a typical human eye will react to, typically about 380 nanometers (violet) to about 780 nanometers (red). In some cases, the surface roughness of the glass is between about 10 nanometers and 30 nanometers.

The conductive layer 504 is on top of the substrate 502. In certain embodiments, one or both of conductive layers 504 and 514 are inorganic and/or solid. Conductive layers 504 and 514 may be made from a variety of different materials including conductive oxides, thin metal coatings, conductive metal nitrides, and composite conductors. Typically, conductive layers 504 and 514 are transparent at least over the wavelength range in which the electrochromic layer is electrochromic. Transparent conductive oxides include metal oxides and metal oxides doped with one or more metals. Examples of such metal oxides and doped metal oxides include indium oxide, indium tin oxide, doped indium oxide, tin dioxide, doped tin dioxide, zinc oxide, aluminum zinc oxide, doped zinc oxide, ruthenium oxide, doped ruthenium oxide, and the like. Since oxides are often used for these layers, they are sometimes referred to as "transparent conductive oxide" (TCO) layers. A thin metallic coating that is substantially transparent may also be used. Examples of metals for such thin metal coatings include transition metals including gold, platinum, silver, aluminum, nickel alloys, and the like. Silver-based thin metal coatings, well known in the glass industry, are also used. Examples of the conductive nitride include titanium nitride, tantalum nitride, titanium oxynitride, and tantalum oxynitride. Conductive layers 504 and 514 may also be composite conductors. Such a composite conductor may be fabricated by placing a pattern of highly conductive ceramic and metal lines or conductive layers on one side of a substrate and then coating it with a transparent conductive material (e.g., doped tin dioxide or indium tin oxide). Ideally, such wires should be thin enough (e.g., about 100 millimeters or less) to be invisible to the naked eye.

In some embodiments, a commercially available substrate (e.g., a glass substrate) comprises a transparent conductive layer coating. Such a product may be used for the substrate 502 and the conductive layer 504. Examples of such glasses include TEC Glass produced by Piercan, tolado, ohio, coated with a conductive layer ^TM Glass sold under the trademark SUNGATE manufactured by PPG Industries of Pittsburgh, pa ^TM 300 and SUNGATE ^TM 500 glass. TEC Glass ^TM Is coated with a fluorinated tin oxide conductive layer. Indium tin oxide is also a commonly used substantially transparent conductive layer.

In some embodiments, the same conductive material is used for both conductive layers (i.e., conductive layers 504 and 514). In some embodiments, each of the conductive layers 504 and 514 uses a different conductive material. For example, in some embodiments, TEC Glass ^TM For substrate 502 (float glass) and conductive layer 504 (fluorinated tin oxide), while indium tin oxide is used for conductive layer 514. As described above, TEC Glass is used in some ^TM In embodiments of (a) the glass substrate 502 and the TEC conductive layer 504 have a sodium diffusion barrier therebetween because float glass can have a very high sodium content.

In some implementations, the composition of the conductive layer (used in fabrication) should be selected or adjusted based on the composition of the adjacent layer (e.g., electrochromic layer 506 or counter electrode layer 510) that is in contact with the conductive layer. For example, for a metal oxide conductive layer, conductivity is a function of the number of oxygen vacancies in the conductive layer material, and the number of oxygen vacancies in the metal oxide is affected by the composition of the adjacent layers. The selection criteria for the conductive layer may also include electrochemical stability of the material and the ability to avoid oxidation or, more generally, reduction by mobile ionic species.

The purpose of the conductive layer is to spread the potential provided by the voltage supply 516 from the surface of the electrochromic stack 520 to the interior region of the stack with a very small ohmic potential drop. The potential is transferred to the conductive layer through an electrical connection to the conductive layer. In some embodiments, bus bars (one in contact with conductive layer 504 and the other in contact with conductive layer 514) provide electrical connection between voltage source 516 and conductive layers 504 and 514. Conductive layers 504 and 514 can also be connected to voltage source 516 by other conventional methods.

In some embodiments, the conductive layers 504 and 514 have a thickness between about 5 nanometers and about 10,000 nanometers. In some embodiments, the conductive layers 504 and 514 have a thickness between about 10 nanometers and about 1,000 nanometers. In other embodiments, the thickness of conductive layers 504 and 514 is between about 10 nanometers and about 500 nanometers. In some TEC Glass ^TM In the embodiment used for the substrate 502 and the conductive layer 504, the conductive layer is approximately 400 nanometers thick. In some indium tin oxide embodiments for conductive layer 514, the conductive layer is approximately 100 nanometers to 400 nanometers thick (280 nanometers in one embodiment). In general, thicker layers of conductive material may be used as long as they provide the necessary electrical properties (e.g., conductivity) and optical properties (e.g., transmittance). In general, conductive layers 504 and 514 are as thin as possible to increase transparency and reduce cost. In certain embodiments, the conductive layer is substantially crystalline. In certain embodiments, the conductive layer is a crystal that is mostly large equiaxed grains.

The thickness of each conductive layer 504 and 514 is also substantially uniform. A smooth layer (i.e., low roughness, ra) of the conductive layer 504 is required so that the other layers of the electrochromic stack 520 are more compliant. In one embodiment, the substantially uniform conductive layer does not vary by more than about + -10% over each of the thicknesses noted above. In another embodiment, the substantially uniform conductive layer varies by no more than about + -5% over each of the thicknesses noted above. In another embodiment, the substantially uniform conductive layer varies by no more than about ±2% over each of the thickness ranges described above.

Due to the relatively large area spanned by the layers, the sheet resistance (R _s ) It is also important. In one placeIn some embodiments, the sheet resistance of conductive layers 504 and 514 is between about 5 ohms per square and about 30 ohms per square. In some embodiments, the sheet resistance of conductive layers 504 and 514 is approximately 15 ohms per square. In general, it is desirable that the sheet resistance of each of the two conductive layers be about the same. In one embodiment, the sheet resistance of each layer is between about 10 ohms and 15 ohms per square.

An electrochromic layer 506 is overlaid on the conductive layer 504. In embodiments, electrochromic layer 506 is inorganic and/or solid, in typical embodiments inorganic and solid. The electrochromic layer may comprise any one or more of a variety of different electrochromic materials, including metal oxides. Such metal oxides include tungsten oxide (WO ₃ ) Molybdenum oxide (MoO) ₃ ) Niobium oxide (Nb) ₂ O ₅ ) Titanium dioxide (TiO) ₂ ) Copper oxide (CuO), iridium oxide (Ir) ₂ O ₃ ) Chromium oxide (Cr) ₂ O ₃ ) Manganese oxide (Mn) ₂ O ₃ ) Vanadium oxide (V) ₂ O ₅ ) Nickel oxide (Ni) ₂ O ₃ ) Cobalt oxide (Co) ₂ O ₃ ) Etc. In some embodiments, the metal oxide is doped with one or more dopants, such as lithium, sodium, potassium, molybdenum, vanadium, titanium, and/or other suitable metals or metal-containing compounds. Mixed oxides (e.g., tungsten-molybdenum oxide, tungsten-vanadium oxide) are also used in certain embodiments. The electrochromic layer 506 including a metal oxide is capable of receiving ions transferred from the counter electrode layer 510.

In some embodiments, tungsten oxide or doped tungsten oxide is used for electrochromic layer 506. In one embodiment, the electrochromic layer consists essentially of WO _x Made, wherein "x" refers to the atomic ratio of oxygen to tungsten in the electrochromic layer, and x is between about 2.7 and 3.5. It has been proposed that only sub-stoichiometric tungsten oxide exhibit electrochromic properties; namely, stoichiometric tungsten oxide (WO ₃ ) No electrochromic is shown. In a more specific embodiment, WO _x (wherein x is less than 3.0 and at least about 2.7) for the electrochromic layer. In another embodiment, the electrochromic is The layer is WOx, where x is between about 2.7 and about 2.9. Some techniques, such as rutherford back-scattering spectroscopy (RBS), are capable of identifying the total number of oxygen atoms, including those that are bound to tungsten as well as those that are not bound to tungsten. In certain examples, the tungsten oxide layer (where x is 3 or greater) exhibits electrochromic properties, possibly due to unbound excess oxygen and sub-stoichiometric tungsten oxide. In another embodiment, the tungsten oxide layer has a stoichiometric or greater amount of oxygen, where x is from 3.0 to about 3.5.

In certain embodiments, the tungsten oxide is in the form of crystals, nanocrystals, or an amorphous form. In some embodiments, the tungsten oxide is substantially nanocrystalline with an average particle size of about 5 nm to about 50 nm (or about 5 nm to about 20 nm), as characterized by Transmission Electron Microscopy (TEM). Tungsten oxide morphology can also be characterized as nanocrystals using x-ray diffraction (XRD). For example, nanocrystalline electrochromic tungsten oxide may have the following XRD characteristics: the crystal size is about 10 nanometers to about 100 nanometers (e.g., about 55 nanometers). Further, nanocrystalline tungsten oxide also exhibits limited long range order, e.g., on the order of a few (about 5 to about 20) tungsten oxide unit cells.

The thickness of the electrochromic layer 506 depends on the electrochromic material selected for the electrochromic layer. In some embodiments, electrochromic layer 506 is about 50 nanometers to 2,000 nanometers, or about 200 nanometers to 700 nanometers. In some embodiments, the electrochromic layer is about 300 nanometers to about 500 nanometers. The thickness of electrochromic layer 506 is also substantially uniform. In one embodiment, the substantially uniform conductive layer varies by only about + -10% within each of the thickness ranges described above. In another embodiment, the substantially uniform conductive layer varies by only about + -5% over each of the thicknesses noted above. In another embodiment, the substantially uniform conductive layer varies by only about ±3% over each of the above thickness ranges.

Generally, in electrochromic materials, the coloration (or optical properties such as any change in absorbance, reflectance, and transmittance) of the electrochromic material is determined by a reversible ion intercalation material (e.g., intercalation) and the corresponding electricityCharge balance electron injection. Typically, some of the ions that cause the optical transition are irreversibly incorporated into the electrochromic material. As explained below, some or all of the irreversibly bound ions are used to compensate for "blind charges" in the material. In most electrochromic materials, suitable ions include lithium ions (Li ⁺ ) And hydrogen ions (H) ⁺ ) (i.e., protons). However, other ions will be suitable in some cases. Such suitable ions include, for example, deuterium ions (D ⁺ ) Sodium ion (Na) ⁺ ) Potassium ion (K) ⁺ ) Calcium ion (Ca) ⁺⁺ ) Barium ion (Ba) ⁺⁺ ) Strontium ion (Sr) ⁺⁺ ) And magnesium ion (Mg) ⁺⁺ ). In various embodiments described herein, lithium ions are used to create electrochromic phenomena. The intercalation of lithium ions into tungsten oxide causes tungsten oxide (WO _3-y (0<y.ltoreq.0.3)) from transparent (fading state) to blue (coloring state).

Referring again to fig. 5, in electrochromic stack 520, ion-conducting layer 508 overlies electrochromic layer 506. A counter electrode layer 510 is on the ion conductive layer 508. In some embodiments, the counter electrode layer 510 is inorganic and/or solid. The counter electrode layer may comprise one or more of a number of different materials that may be used to store ions when the electrochromic device is in a fade state. During the electrochromic transition (e.g., initiated by application of a suitable potential), the counter electrode layer transfers some or all of its stored ions to the electrochromic layer, causing the electrochromic layer to change to a colored state. Meanwhile, in the case of NiWO, the counter electrode layer is colored with ion loss.

In some embodiments, suitable for counter electrodes and WO ₃ Complementary materials include nickel oxide (NiO), nickel tungsten oxide (NiWO), nickel vanadium oxide, nickel chromium oxide, nickel aluminum oxide, nickel manganese oxide, nickel magnesium oxide, chromium oxide (Cr) ₂ O ₃ ) Manganese oxide (MnO) ₂ ) And Prussian blue. The optically inert counter electrode comprises cerium titanium oxide (CeO) ₂ -TiO ₂ ) Cerium zirconium oxide (CeO) ₂ -ZrO ₂ ) Nickel oxide (NiO), nickel tungsten oxide (NiWO), vanadium oxide (V) ₂ O ₅ ) And mixtures of oxides(e.g., ni ₂ O ₃ And WO ₃ Is a mixture of (a) and (b). Doped formulations of these oxides may also be used, with dopants including, for example, tantalum and tungsten. Since the counter electrode layer 510 contains ions for generating an electrochromic phenomenon in the electrochromic material when the electrochromic material is in a discolored state, it is preferable that it has high transmittance and neutral color when the counter electrode contains a large amount of such ions.

In some embodiments, nickel tungsten oxide (NiWO) is used for the counter electrode layer. In certain embodiments, the amount of nickel in the nickel tungsten oxide may be up to about 90% by weight of the nickel tungsten oxide. In particular embodiments, the mass ratio of nickel to tungsten in the nickel tungsten oxide is between about 4:6 and 6:4 (e.g., about 1:1). In one embodiment, ni of the NiWO is between about 15% (at) and about 60%; w is between about 10% and about 40%; o is between about 30% and about 75%. In another embodiment, ni of the NiWO is between about 30 atomic percent and about 45 percent; w is between about 10% and about 25%; o is between about 35% and about 50%. In one embodiment, nickel (atom) of NiWO is about 42%, W is about 14%, and O is about 44%.

When charge is removed from the counter electrode 510 made of nickel tungsten oxide (i.e., ions are transported from the counter electrode 510 to the electrochromic layer 506), the counter electrode layer will change from a transparent state to a brown colored state.

The morphology of the counter electrode may be crystalline, nanocrystalline or amorphous. In some embodiments, wherein the counter electrode layer is nickel tungsten oxide, the counter electrode material is amorphous or substantially amorphous. It has been found that under certain conditions, a nickel tungsten oxide counter electrode that is substantially amorphous performs better than its crystalline counterpart. The amorphous state of nickel tungsten oxide can be obtained by using certain process conditions described below. While not wishing to be bound by any theory or mechanism, it is believed that the amorphous nickel tungsten oxide is generated by relatively high energy atoms in the sputtering process. Higher energy atoms are obtained in sputtering processes where, for example, the target power is higher, the chamber pressure is lower (i.e., higher vacuum), and the power supply to substrate distance is smaller. Under the process conditions described, films with higher density and better stability when exposed to uv/heat are produced.

In some embodiments, the counter electrode has a thickness of about 50 nanometers to about 650 nanometers. In some embodiments, the counter electrode has a thickness of about 100 nm to about 400 nm, preferably in the range of about 200 nm to 300 nm. The thickness of the counter electrode layer 510 is also substantially uniform. In one embodiment, the substantially uniform counter electrode layer varies by only about + -10% over each of the thickness ranges described above. In another embodiment, the substantially uniform counter electrode layer varies by only about + -5% over each of the thickness ranges described above. In another embodiment, the substantially uniform counter electrode layer varies by only about + -3% over each of the thickness ranges described above.

During the fade state (and, correspondingly, during the state in which the electrochromic layer is colored), the amount of ions stored within the counter electrode layer and available to drive the electrochromic transition depends on the composition of the layer as well as the thickness of the layer and the method of manufacture. Both the electrochromic layer and the counter electrode layer are capable of supporting available charge (in the form of lithium ions and electrons) of the order of tens of milli-bases per square centimeter of layer surface area. The charge capacity of an electrochromic film is the amount of charge that is reversibly loaded and unloaded per unit area and unit thickness of the film by application of an external voltage or potential. In one embodiment, WO ₃ The charge capacity of the layer is between about 30 and about 150mC/cm ² Between/micron. In another embodiment, WO ₃ The charge capacity of the layer is between about 50 and about 100mC/cm ² Between/micron. In one embodiment, the charge capacity of the NiWO layer is between about 75 and about 200mC/cm ² Between/micron. In another embodiment, the charge capacity of the NiWO layer is between about 100 and about 150mC/cm ² Between/micron.

In electrochromic devices having different layers, there is an ion conducting layer 508 between electrochromic layer 506 and counter electrode layer 510. The ion conductive layer 508 serves as a medium when the electrochromic device is switched between a fade state and a color stateAs a result, ions are transported through it (in the form of an electrolyte). Preferably, the ion conductive layer 508 has a high conductivity for the relevant ions for electrochromic and counter electrode layers, but an electron conductivity that is so low that electron transfer occurring during normal operation is negligible. The thin ion conducting layer, which is highly ion conductive, allows for rapid ion conduction, thus enabling rapid switching of the high performance electrochromic device. In certain embodiments, the ion conductive layer 508 is inorganic and/or solid. When materials are utilized and fabricated in a manner that produces relatively few defects, the ion conductor layer can be made very thin to produce high performance devices. In various implementations, the ion conductor material has an ionic conductivity of about 10 ⁸ Siemens/cm or ohm ^-1 cm ^-1 And about 10 ⁹ Siemens/cm or ohm ^-1 cm ^-1 Between which the resistance is about 10 ¹¹ ohms-cm。

Examples of suitable ion conducting layers (for electrochromic devices with different IC layers) include silicate, silicon oxide, tungsten oxide, tantalum oxide, niobium oxide, and borates. The silicon oxide includes silicon aluminum oxide. These materials may be doped with different dopants, including lithium. The lithium doped silicon oxide includes lithium silicon aluminum oxide. In some embodiments, the ion-conducting layer comprises a silicate-based structure. In other embodiments, suitable ion conductors (particularly suitable for lithium ion transport) include, but are not limited to, lithium silicate, lithium aluminum borate, lithium aluminum fluoride, lithium borate, lithium nitride, lithium zirconium silicate, lithium niobate, lithium borosilicate, lithium phosphosilicate, and other such lithium-based ceramic materials, silica, or silicon oxides, including lithium silicon oxide. However, any material may be used for the ion-conducting layer 508, provided that it has a low defect rate and allows ions to pass between the counter electrode layer 510 and the electrochromic layer 506 while substantially blocking electrons from passing therethrough at the time of manufacture.

In certain embodiments, the ion-conducting layer is in the form of crystals, nanocrystals, or an amorphous form. Typically, the ion conductive layer is amorphous. In another embodiment, the ion conducting layer is a nanocrystal. In yet another embodiment, the ion conducting layer is crystalline.

In some embodiments, silicon aluminum oxide (SiAlO) is used for the ion conductive layer 508. In a specific embodiment, the silicon/aluminum target used to fabricate the ion conductor layer by sputtering comprises an atomic percent of aluminum between about 6 and about 20. This defines the ratio of silicon to aluminum in the ion-conducting layer. In some embodiments, the silicon aluminum oxide ion conductive layer 508 is amorphous.

The thickness of the ion conductive layer 508 depends on the material. In some embodiments, the ion conductive layer 508 is about 5 nm to 100 nm thick, preferably about 10 nm to 60 nm thick. In some embodiments, the ion conducting layer is about 15 nm to 40 nm thick, or about 25 nm to 30 nm thick. The thickness of the ion-conducting layer is also substantially uniform. In one embodiment, the substantially uniform ion conductive layer varies by no more than about + -10% over each of the thicknesses noted above. In another embodiment, the substantially uniform ion conductive layer varies by no more than about + -5% over each of the thicknesses noted above. In another embodiment, the substantially uniform ion conductive layer varies by no more than about + -3% over each of the thicknesses noted above.

Ions transported through the ion-conducting layer between the electrochromic layer and the counter electrode layer are used to effect a color change in the electrochromic layer (i.e., change the electrochromic device from a fade state to a color state). Depending on the material selected for the electrochromic device stack, such ions include lithium ions (Li ⁺ ) And hydrogen ions (H) ⁺ ) (i.e., protons). As noted above, other ions may also be used in certain embodiments. These ions include, for example, deuterium ions (D ⁺ ) Sodium ion (Na) ⁺ ) Potassium ion (K) ⁺ ) Calcium ion (Ca) ⁺⁺ ) Barium ion (Ba) ⁺⁺ ) Strontium ion (Sr) ⁺⁺ ) And magnesium ion (Mg) ⁺⁺ )。

As described above, the ion conductive layer 508 should have very few defects. Among other problems, defects in the ion-conducting layer can cause a short circuit between the electrochromic layer and the counter electrode layer (described in more detail below in connection with fig. 5). A short circuit occurs when electrical communication is established between the oppositely charged conductive layers, e.g., a conductive particle contacts each of the two conductive and charged layers (as opposed to a "pinhole," which is a defect that does not cause a short circuit between the oppositely charged conductive layers). When a short circuit occurs, electrons rather than ions migrate between the electrochromic layer and the counter electrode, which typically results in a bright spot at the location of the short circuit when the electrochromic device is otherwise in a colored state (i.e., a spot when the window is not transitioning but remains open colored (often much shallower than the colored state). Preferably, the ion conductive layer is as thin as possible, and no short circuit occurs between the electrochromic layer and the counter electrode layer. As shown, the low defect rate of ion-conducting layer 508 (or elsewhere in the electrochromic device) allows ion-conducting layer 508 to be thinner. When a thin ion conducting layer is used, ion transport between the electrochromic layer and the counter electrode layer with electrochemical cycling is faster. In general terms, the defect rate criteria specified herein may be applied to any particular layer in the stack (ion conductive layer or otherwise) or to the stack as a whole, or any portion of the stack. Defect rate criteria are discussed further below.

Electrochromic device 500 may include one or more additional layers (not shown), such as one or more passivation layers. Passivation layers for improving certain optical properties may be included in electrochromic device 500. A passivation layer for providing moisture or scratch resistance may also be included in the electrochromic device 500. For example, the conductive layer may also be treated with an anti-reflective or protective oxide or nitride layer. Other passivation layers may be used to hermetically seal electrochromic device 500.

Fig. 6A is a schematic cross-section of an electrochromic device in a fade state (or transition to a fade state). According to a specific embodiment, electrochromic device 600 includes a tungsten oxide electrochromic layer (EC) 606 and a nickel tungsten oxide counter electrode layer (CE) 610. In some cases, the tungsten oxide electrochromic layer 606 has a nanocrystalline morphology, or substantially nanocrystalline morphology. In some embodiments, wherein the counter electrode layer 610 is nickel tungsten oxide, the counter electrode material is amorphous or substantially amorphous. In some embodiments, the weight percent of tungsten to nickel in the nickel tungsten oxide is about 0.40 to about 0.60.

Electrochromic device600 also includes a substrate 602, a Conductive Layer (CL) 604, an ion conductive layer (IC) 608, and a Conductive Layer (CL) 614. In some embodiments, the substrate 602 and the conductive layer 604 together comprise TEC-Glass ^TM . As shown, electrochromic devices described herein, such as those described in fig. 6A, often find use with architectural glass to be beneficial. Thus, in some embodiments, the substrate 602 is sized so that it can be divided into architectural glass. In some embodiments, conductive layer 614 is Indium Tin Oxide (ITO). In some embodiments, the ion conductive layer 608 is a silicon aluminum oxide.

The voltage source 616 is configured to apply an electrical potential to the electrochromic stack 620 through suitable connections (e.g., bus bars) to the conductive layers 604 and 614. In some embodiments, the voltage source is configured to apply a potential of about 2 volts to drive the device from one optical state to another. The polarity of the potential as shown in fig. 6A is such that ions (lithium ions in this example) are mainly present (as indicated by the dashed arrows) in the nickel tungsten oxide counter electrode layer 610.

In embodiments in which tungsten oxide is used as the electrochromic layer and nickel tungsten oxide is used as the counter electrode layer, the ratio of electrochromic layer thickness to counter electrode layer thickness may be about 1.7:1 to 2.3:1 (e.g., about 2:1). In some embodiments, the electrochromic tungsten oxide layer is about 200 nm to 700 nm thick. In a further embodiment, the electrochromic tungsten oxide layer is about 400 nanometers to 500 nanometers thick. In some embodiments, the nickel tungsten oxide counter electrode layer is about 100 nm to 350 nm thick. In a further embodiment, the nickel tungsten oxide counter electrode layer is about 200 nm to 250 nm thick. In a further embodiment, the nickel tungsten oxide counter electrode layer is about 240 nanometers thick. Further, in some embodiments, the silicon aluminum oxide ion conductive layer 608 is approximately 10 nanometers to 100 nanometers thick. In a further embodiment, the silicon aluminum oxide ion conducting layer is about 20 nm to 50 nm thick.

As indicated above, the electrochromic material may contain blind charges. Blind charges in electrochromic materials are charges (e.g., negative charges in the case of tungsten oxide electrochromic materials) that are present in the material at the time of manufacture, compensated by oppositely charged ions or other charge carriers. For example, in the case of tungsten oxide, the amount of blind charge depends on the concentration of excess oxygen during sputtering of tungsten oxide. Functionally, the blind charge must be compensated before the ions used to transform the electrochromic material can effectively change the optical properties of the electrochromic material. If the blind charge is not precompensated, ions provided to the electrochromic material will irreversibly incorporate into the material and not contribute to the optical state of the material. Thus, electrochromic devices are typically provided with a sufficient amount of ions (e.g., lithium ions or protons) to both compensate for the blind charge and provide ions for reversibly switching the electrochromic material between two optical states. In many known electrochromic devices, charge is lost during the first electrochemical cycle to compensate for blind charge.

In some embodiments, a sufficient amount of lithium is present in electrochromic stack 620 to compensate for the blind charge in electrochromic layer 606, and then an additional amount of lithium (by mass) is present in the stack (first present in, for example, counter electrode layer 610) that is about 1.5 to 2.5 times the amount of lithium used to compensate for the blind charge. That is, approximately 1.5 to 2.5 times the amount of lithium is required to compensate for the blind charge for the reversible cycling between the electrochromic layer 606 and the counter electrode layer 610 in the electrochromic stack 620. In some embodiments, there is enough lithium in the electrochromic stack 620 to compensate for the blind charge in the electrochromic layer 606, and then approximately twice the amount of this lithium (by mass) is present to the electrode layer 610 or elsewhere in the stack.

Fig. 6B is a schematic cross-section of the electrochromic device 600 shown in fig. 6A but in a colored state (or transitioned to a colored state). In fig. 6B, the polarity of the voltage source 616 is reversed, so the electrochromic layer becomes more negative and no longer accepts additional lithium ions, transitioning to the colored state. As indicated by the dashed arrows, lithium ions are transported through the ion conductive layer 608 to the tungsten oxide electrochromic layer 606. The tungsten oxide electrochromic layer 606 is shown in a colored state. The nickel tungsten oxide counter electrode 610 is also shown in a colored state. As explained, nickel tungsten oxide gradually becomes increasingly opaque as it gives up (releases) lithium ions. In this example, there is a synergistic effect in which the transition of layers 606 and 610 to the colored state adds up in a direction that reduces the amount of light transmitted through the stack and substrate.

The above-described all-solid state and inorganic electrochromic devices have low defect rates and high reliability and are therefore particularly suitable for the embodiments described herein. Other low defect rate all solid state inorganic electrochromic devices are described below.

Low defect rate solid state electrochromic device with different IC layers

As described above, electrochromic devices typically include an electrochromic ("EC") electrode layer and a counter electrode ("CE") layer separated by an ion conductive ("IC") layer having high conductivity to ions and high resistance to electrons. As is generally understood, the ion conductive layer may thus prevent a short circuit from occurring between the electrochromic layer and the counter electrode layer. The ion conductive layer allows the electrochromic electrode and the counter electrode to retain an electrical charge, thereby maintaining their discolored or colored state. In electrochromic devices having different layers, the components form a stack that includes an ion-conducting layer sandwiched between an electrochromic electrode layer and a counter electrode layer. The boundaries between the three components of the stack are determined by abrupt changes in composition and/or microstructure. Thus, the device has three different layers and two abrupt interfaces.

Very surprisingly, it has been found that high quality electrochromic devices can be fabricated without depositing an ion conducting electrically insulating layer. According to certain embodiments, the counter electrode and electrochromic electrode are formed in close proximity to each other, often in direct contact, without the need for separate deposition of an ion conducting layer. It is believed that various manufacturing processes and/or physical or chemical mechanisms create an interface region between the contacting electrochromic layer and the counter electrode layer, and that this interface region performs at least some of the functions of the ion-conductive electrically insulating layer in the device (with the ion-conductive electrically insulating layer).

In some embodiments, such electrochromic devices having ion-conductive electrically insulating interface regions, rather than distinct IC layers, are used in one or more panes of the multi-pane window units described herein. The inventors of the present invention describe such devices and methods of making the same as described in U.S. patent application Ser. Nos. 12/772,055 and 12/772,075, filed on 4 months and 30 days of 2010, and U.S. patent application Ser. Nos. 12/814,277 and 12/814,279, filed on 6 months and 11 days of 2010, respectively, the disclosures of which are incorporated herein by reference for all purposes. These electrochromic devices can be manufactured with low defectivity and are therefore particularly suitable for the multi-pane window units described herein. These devices are briefly described below.

Fig. 7 is a schematic cross-section of an electrochromic device 500 in a colored state, where the device has ion-conducting, electrically insulating interface regions 708 that function as different IC layers. The voltage source 616, conductive layers 614 and 604, and substrate 602 are substantially the same as described in connection with fig. 6A and 6B. Between conductive layers 614 and 604 is region 710, which includes counter electrode layer 610, electrochromic layer 606, and ion-conductive electrically insulating interface region 708 therebetween, rather than a different IC layer. In this example, there is no distinct boundary between counter electrode layer 610 and interface region 708, nor is there a distinct boundary between electrochromic layer 606 and interface region 708. Instead, there is a diffuse transition between the CE layer 610 and the interface region 708, and between the interface region 708 and the EC layer 606. The conventional wisdom is that each of the three layers should be laid down as different uniformly deposited and smooth layers to form a stack. The interface between each layer should be "transparent" with no material mixing at the interface of each layer. One of ordinary skill in the art will recognize that in practice there is an unavoidable degree of material mixing at the interface of the layers, but mainly any such mixing is unintentional and minimal in conventional manufacturing methods. The inventors have found that an interface region can be formed that serves as an interface region for the IC layer, wherein the interface region includes a significant amount of one or more electrochromic materials and/or counter electrode materials, depending on the design. This fundamentally departs from the conventional manufacturing method. These all-solid-state inorganic electrochromic devices also have low defect rates and high reliability and are therefore particularly suitable for use in the embodiments described herein.

Visual defects in electrochromic devices

As indicated above, almost any electrochromic device may be used in the multi-pane window units described herein, as the low probability that a defect will be perfectly aligned such that when both panes of the window are darkened, the user will actually see the defect) counteracts the visual defect present in the overlapping device (e.g., the overlapping device on each of the two panes of a double pane window unit). The number of defects of electrochromic devices (as described above) has been reduced; i.e. much less defective than comparable prior devices, and is therefore particularly suitable for the described embodiments.

As used herein, the term "defect" refers to a defective spot or area of an electrochromic device. Defects may be caused by electrical shorts or pinholes. In addition, the defect may be visible or invisible. Often, the defect will be represented as a visually discernable anomaly in an electrochromic window or other device. Such defects are referred to herein as "visible" defects. Other defects are so small that they do not visually draw the viewer's attention during normal use (e.g., such defects do not produce noticeable light spots when the device is in a colored state during the day). A "short" is a local conductive path (e.g., a conductive path between two TCO layers) across the ion conductive layer. A "pinhole" is a region where one or more layers of an electrochromic device are lost or damaged and therefore cannot exhibit electrochromic. The aperture is not an electrical short. Three types of defects are of primary concern: (1) a visible pinhole, (2) a visible short circuit, and (3) an invisible short circuit. Typically, although not necessarily, the visible short will have a defect size of at least about 3 microns, which results in a region of, for example, about 1cm in diameter (where the electrochromic effect of the region is perceived to be diminished), which can be greatly reduced by isolating the defect that caused the visible short (e.g., by laser scribing the defect) so that the visible short seen by the naked eye is only similar to a visible pinhole. The defect size of the visible pinholes is at least about 100 microns and is therefore more visually indistinguishable than a visible short circuit. One aspect of the present invention aims to reduce (if not eliminate) the number of visual defects actually observed by the end user.

In some cases, the electrical short is caused by conductive particles deposited on the ion conductive layer, thereby creating an electron path between the counter electrode layer and the electrochromic layer or the TCO connected to either. In certain other cases, defects are caused by particles on the substrate (on which the electrochromic stack is fabricated) and such particles cause delamination of the layer (sometimes referred to as "pop-off") or result in the layer not adhering to the substrate. Figures 5 and 6A-6B below illustrate two types of defects. If delamination or abrupt detachment defects occur before depositing the TCO or the attached EC or CE, the delamination or abrupt detachment defects may cause a short circuit. In this case, the subsequently deposited TCO or EC/CE layer will directly contact the underlying TCO or CE/EC layer providing a direct electron conduction path. Table 2 below shows some examples of sources of defects. Table 2 is intended to provide examples of mechanisms that result in different types of visible and invisible defects. There are additional factors that can influence how the EC window responds to defects within the stack.

An electrical short (even if not visible) can cause leakage current through the ion conducting layer and result in a potential drop near the short. If the potential drop is large enough, it will prevent the electrochromic device from electrochromic transitions near the short. In the case of a visible short circuit, the defect will appear as an optical centre region with a diffusion boundary (when the device is in a coloured state) so that the device becomes progressively darker with the distance from the centre of the short circuit. If the area of the electrochromic device concentrates a large number of electrical shorts (visible or invisible), they together can affect the broad area of the device, thereby rendering the device incapable of switching in such area. This is because the potential difference between the EC and CE layers of such regions does not achieve the desired threshold level of driving ions through the ion conducting layer.

In some implementations described herein, the shorts (visible and invisible) are well controlled, so leakage currents do not have such an effect anywhere in the device. It should be appreciated that other causes may also lead to leakage currents in addition to short-circuit type defects. Such other causes include extensive leakage through the ion-conducting layer, as well as edge defects, such as roll-off defects and scribe line defects described elsewhere herein. It is emphasized here that leakage is caused only by the point of electrical shorting through the ion conducting layer (or interface region) in the interior region of the electrochromic device. It should be noted, however, that electrochromic devices (as described above) using the interface region as the IC layer may have higher than generally acceptable leakage currents, but the device exhibits good performance. However, visual defects still appear in these electrochromic devices.

Fig. 8 is a schematic cross-section of an electrochromic device 800 in which particles within the ion-conducting layer cause localized defects within the device. The depicted device 800 has typically different layers, although particles in this size range will cause visual defects in electrochromic devices that also use ion-conductive, electrically insulating interface regions. Electrochromic device 800 includes the same components as electrochromic device 600 depicted in fig. 6A. However, in the ion-conducting layer 608 of the electrochromic device 800, there are conductive particles 802 or other artifacts that cause defects. The conductive particles 802 cause a short circuit between the electrochromic layer 606 and the counter electrode layer 610. The short does not allow ions to flow between the electrochromic layer 606 and the counter electrode layer 610, but rather allows electrons to pass locally between the layers, which causes the electrochromic layer 606 to appear as transparent areas 804 and the counter electrode layer 610 to appear as transparent areas 806 when the remainder of the layers 610 and 606 are in a colored state. That is, if electrochromic device 800 is in a colored state, conductive particles 802 render areas 804 and 806 of the electrochromic device unable to enter the colored state. These defective areas are sometimes referred to as "constellations" because they appear as a series of bright spots (or stars) against a dark background (the remainder of the device in a colored state). One will naturally notice the constellation and often find it distracting and unsightly.

Fig. 9A is a schematic cross-section of an electrochromic device 900 having particles 902 or other debris on a conductive layer 604 prior to depositing the remainder of the electrochromic stack. Electrochromic device 900 includes the same components as electrochromic device 600. Since the conformal layers 606-610 are deposited sequentially over the particles 902, as described (in this example, layer 614 is not deposited), the particles 902 cause the layers in the electrochromic stack 620 to expand in the region of the particles 902. While not wishing to be bound by a particular theory, it is believed that layering on such particles (assuming the layers are relatively thin) may create pressure in the region where expansion is formed. More specifically, defects may be present in each layer around the periphery of the expanded region, such as cracks or voids arranged in a lattice or at a macroscopic level. One result of these defects would be, for example, an electrical short between electrochromic layer 606 and counter electrode layer 610, or a loss of ionic conductivity within layer 608. However, these defects are not depicted in fig. 9A.

Referring to fig. 9B, another result of the defect caused by particle 902 is referred to as "pop-off". In this example, a portion of the conductive layer 604 in the region of the particles 902 separates out and carries a portion of the electrochromic layer 606, the ion conductive layer 608, and the counter electrode layer 610 prior to depositing the conductive layer 614. "abrupt release" is a block 904 that includes particles 902, a portion of electrochromic layer 606, and ion-conducting layer 608 and counter electrode layer 610. The result is that regions of conductive layer 604 are exposed. Referring to fig. 9C, after the abrupt release and once conductive layer 614 is deposited, an electrical short is formed in which conductive layer 614 is in contact with conductive layer 604. When electrochromic device 900 is in a colored state, the electrical shorts will create transparent areas therein, similar in appearance to the defects created by shorts described above in connection with fig. 8.

Abrupt detachment defects (as described above) due to particles or debris on the substrate 602 or 604 may also occur in the ion conducting layer 608 and the counter electrode layer 610, resulting in pinhole defects when the electrochromic device is in a colored state.

Even after isolating and minimizing such defects, for example, using laser scribing, the end result of the above-described defects is a constellation, electrical shorts, and other defects result in pinholes. Thus, it is desirable to use low defect rate electrochromic devices to reduce the total number of pinholes that remain after mitigation efforts. The following is a brief description of an integrated system for manufacturing such low defect rate all-solid-state inorganic electrochromic devices on a construction grade substrate.

Low defect rate electrochromic device

The electrochromic device described above may be fabricated in an integrated deposition system, for example on architectural glass. Electrochromic devices are used to manufacture window units, such as IGUs, which in turn are used to manufacture electrochromic windows. The term "integrated deposition system" refers to an apparatus for fabricating electrochromic devices on optically transparent and translucent substrates. The apparatus has a plurality of stations, each station dedicated to a particular unit operation, such as depositing a particular component (or portion of a component) of an electrochromic device, and cleaning, etching, and controlling the temperature of such device or a portion thereof. The stations are fully integrated so that the substrate on which the electrochromic device is fabricated can pass from one station to the next without exposure to the external environment. The integrated deposition system operates within a system provided with process stations under controlled ambient conditions. An exemplary integrated deposition system is described in connection with fig. 9.

Fig. 10 depicts, in perspective schematic form, an integrated deposition system 1000 in accordance with certain embodiments. In this example, the system 1000 includes an ingress load lock 1002 for introducing a substrate into the system and an egress load lock 1004 for removing a substrate from the system. Load lock allows substrates to be introduced into and removed from the system without disturbing the controlled environment of the system. The integrated deposition system 1000 has a module 1006 with a plurality of deposition stations that deposit various layers of an electrochromic stack, such as those described above. Various stations within the integrated deposition system may include heaters, coolers, various sputter targets, as well as tools for moving sputter targets, RF and/or DC power supplies and power delivery mechanisms, etching tools (e.g., plasma etching), gas sources, vacuum sources, glow discharge sources, process parameter monitors and sensors, robots, power supplies, and the like.

Having an inlet end 1010 for a load, such as an architectural glass substrate 1025 (load lock 1004 has a corresponding outlet end). Substrate 1025 is supported by tray 1020 which moves along track 1015. The tray 1020 may be translated forward and/or backward (as indicated by the double-headed arrow) through the system 1000 as desired by one or more deposition processes. In this example, tray 1020 and substrate 1025 are oriented substantially vertically. The substantially vertical orientation helps to avoid defects because particulate matter that may result from, for example, agglomeration of atoms by sputtering, will be susceptible to gravity and thus not deposit on substrate 1025. In addition, because architectural glass substrates tend to be larger, the vertical orientation of the substrate enables thinner glass substrates to be coated as the substrate passes through the stations of the integrated deposition system with less concern for sagging that would occur with thicker hot glass.

The target 1030 (in this case a cylindrical target) is oriented parallel to and in front of the substrate surface where deposition will occur (other sputtering tools are not described herein for convenience). Substrate 1025 can translate past target 1030 during deposition and/or target 1030 can move in front of substrate 1025.

The integrated deposition system 1000 also has various vacuum pumps, air inlets, pressure sensors, etc. that establish and maintain a controlled ambient environment within the system. These components are not shown, but will be understood by one of ordinary skill in the art. The system 1000 is controlled by, for example, a computer system or other controller (represented in FIG. 10 as an LCD and keyboard 1035). One of ordinary skill in the art will appreciate that embodiments of the invention may employ various processes involving data stored in or transferred through one or more computer systems. The control device may be specially constructed for the required purposes, or it may be a general purpose computer selectively activated or reconfigured by a computer program and/or data structure stored in the computer.

By using such an integrated deposition system, electrochromic devices with very low defect rates can be produced. In one embodiment, the number of visible pinhole defects in a single electrochromic device is no greater than about 0.04 per square centimeter. In another embodiment, the number of visible pinhole defects in a single electrochromic device is no greater than about 0.02 per square centimeter, and in more particular embodiments, the number of such defects is no greater than about 0.01 per square centimeter.

As mentioned above, the visible short-circuit type defects are typically treated separately after manufacture, for example, separated by laser scribing, leaving only small holes associated with the short-circuits as visible defects. In one embodiment, the number of short-circuit-related visible pinhole defects in a single electrochromic device is no greater than about 0.005 per square centimeter. In another embodiment, the number of short-circuit-related visible pinhole defects in a single electrochromic device is no greater than about 0.003 per square centimeter, and in more particular embodiments, the number of such defects is no greater than about 0.001 per square centimeter. In one embodiment, the total amount of visual defects, pinholes, and short-circuit related pinholes resulting from separating short-circuit related defects in a single device is less than about 0.1 defects per square centimeter, in another embodiment less than about 0.08 defects per square centimeter, and in another embodiment less than about 0.045 defects per square centimeter (less than about 450 defects per square meter of window).

In conventional electrochromic windows, one pane of electrochromic glass is incorporated into the IGU. The IGU comprises multiple glass panes assembled into a unit, the intention being generally to maximize the thermal insulation of the gases contained within the space formed by the unit, while providing clear vision through the unit. In addition to electrical leads for connecting the electrochromic glazing to a voltage source, the hollow glazing unit of electrochromic glazing is combined with an IGU currently known in the art. Because electrochromic IGUs are subjected to higher temperatures (because electrochromic glass absorbs radiant energy), they require stronger sealants than those used by conventional IGUs. Such as stainless steel spacer bars, high temperature Polyisobutylene (PIB), new secondary sealants, foil coated PIB tape for spacer joints, and the like.

Although the electrochromic devices described above have very low defect rates, there are still visual defects. And since generally an IGU comprises only one pane with electrochromic devices, even if such an IGU comprises low defect rate devices, at least a small number of defects are still evident when the window is in a tinted state.

While the foregoing invention has been described in some detail to aid understanding, the described embodiments are to be considered as illustrative and not restrictive. It will be apparent to a person skilled in the art that certain changes and modifications may be practiced within the scope of the appended claims.

Claims

1. An electrochromic privacy window, comprising:

a first substantially transparent substrate having a first electrochromic device disposed thereon; and

a second substantially transparent substrate having a second electrochromic device disposed thereon,

wherein the first and second substantially transparent substrates are aligned, one in front of the other, and the electrochromic privacy window is configured to transition the first electrochromic device and/or the second electrochromic device to a plurality of optical states of the electrochromic privacy window, including a dark optical state for privacy protection;

Wherein the transition of the first electrochromic device is complementary to the transition of the second electrochromic device such that the overall shading effect is minimized, and

wherein the first electrochromic device and the second electrochromic device are all solid state.

2. The electrochromic privacy window of claim 1, wherein the dark optical state is a transmittance of between 0.1% and 5%.

3. The electrochromic privacy window of claim 1, wherein one or both of the first electrochromic device and the second electrochromic device are two-state electrochromic devices.

4. The electrochromic privacy window of claim 1, wherein the plurality of optical states further comprises four optical states.

5. The electrochromic privacy window of claim 4, wherein the four optical states have:

i) A total transmission between 60% and 90%;

ii) a total transmittance of between 15% and 30%;

iii) A total transmittance of between 5% and 10%; and

iv) a total transmission between 0.1% and 5%.

6. The electrochromic privacy window of claim 1, wherein at least one of the first substantially transparent substrate and the second substantially transparent substrate comprises architectural glass.

7. The electrochromic privacy window of claim 1,

wherein the electrochromic privacy window is in the form of a hollow glass unit; and

wherein at least one of the first electrochromic device and the second electrochromic device is on a surface facing an interior region of the hollow glass unit.

8. The electrochromic privacy window of claim 1, further comprising an interior region between the first substantially transparent substrate and the second substantially transparent substrate, the interior region comprising a gas.

9. The electrochromic privacy window of claim 1, wherein at least one of the first electrochromic device and the second electrochromic device has a transparent conductive oxide layer configured to be heated independent of operation of the at least one of the electrochromic devices, the transparent conductive oxide layer being a component of the at least one of the first electrochromic device and the second electrochromic device.

10. The electrochromic privacy window of claim 1, wherein at least one of the first substantially transparent substrate and the second substantially transparent substrate further comprises a low emissivity coating.

11. The electrochromic privacy window of claim 1, wherein each of the first electrochromic device and the second electrochromic device comprises a tungsten oxide or doped tungsten oxide electrochromic layer and a nickel tungsten oxide counter electrode optionally doped with tantalum.

12. The electrochromic privacy window of claim 1, wherein each of the first electrochromic device and the second electrochromic device comprises a tungsten oxide or doped tungsten oxide electrochromic layer having 75 to 200mC/cm ² Charge capacity between/microns.

13. The electrochromic privacy window of claim 1, wherein each of the first electrochromic device and the second electrochromic device comprises a nickel tungsten oxide counter electrode selectively doped with tantalum, the nickel tungsten oxide counter electrode having 75 to 200mC/cm ² Charge capacity between/microns.

14. The electrochromic privacy window of claim 1, wherein each of the first electrochromic device and the second electrochromic device comprises an electrochromic layer and a counter electrode layer, wherein the ratio of the thickness of the electrochromic layer to the thickness of the counter electrode layer is between 1.7:1 and 2.3:1.

15. The electrochromic privacy window of claim 1, wherein the second substantially transparent substrate further comprises one or more of: ultraviolet absorbing and/or reflecting coatings, and infrared absorbing and/or reflecting coatings, and low emissivity coatings.

16. The electrochromic privacy window of claim 1, further comprising a controller electrically connected with the first electrochromic device and the second electrochromic device, the controller configured to share charge between the first electrochromic device and the second electrochromic device.

17. The electrochromic privacy window of claim 1,

further comprising a transparent conductive oxide layer, which is not part of the first electrochromic device or part of the second electrochromic device,

wherein the transparent conductive oxide layer is configured to be resistively heated by application of electricity during operation,

wherein the resistive heating of the transparent conductive oxide layer is configured to facilitate low temperature switching of at least one of the first electrochromic device and the second electrochromic device.

18. The electrochromic privacy window of claim 1, wherein at least one of the first electrochromic device and the second electrochromic device is on an interior surface.

19. A method of manufacturing a window unit, the method comprising:

substantially parallel a first substantially transparent substrate having a first electrochromic device disposed thereon and a second substantially transparent substrate having a second electrochromic device disposed thereon; and

installing a sealing barrier between the first and second substantially transparent substrates, the sealing barrier defining with the first and second substantially transparent substrates an interior region in the hollow glass unit, the interior region being thermally insulated,

wherein the first and second electrochromic devices are both two-state electrochromic devices and the manufactured window unit has at least four optical states,

wherein at least one of the first electrochromic device and the second electrochromic device is an all-solid-state inorganic device, and

wherein the interior region comprises an inert gas.

20. The method of claim 19, wherein at least one of the first and second substantially transparent substrates comprises architectural glass.

21. The method of claim 19, wherein at least one of the first and second substantially transparent substrates comprises a low emissivity coating.

22. The method of claim 19, wherein the first electrochromic device and the second electrochromic device both face the interior region.

23. The method of claim 19, wherein the transmittance of the low transmission state of the first electrochromic device is between about 5% and about 15%, and the transmittance of the high transmission state of the first electrochromic device is between about 75% and about 95%; and the transmittance of the low transmission state of the second electrochromic device is between about 20% and about 30%, and the transmittance of the high transmission state of the second electrochromic device is between about 75% and about 95%.

24. The method of claim 19, wherein the at least four optical states are:

i) The total transmittance is between about 60% and about 90%;

ii) a total transmittance of between about 15% and about 30%;

iii) The total transmittance is between about 5% and about 10%; and

iv) a total transmittance of between about 0.1% and about 5%.

25. The method of claim 19, wherein the sealing barrier hermetically seals the interior region.

26. A multi-pane electrochromic window comprising two or more electrochromic devices, each of the two or more electrochromic devices being located on separate panes of the multi-pane electrochromic window, and each of the two or more electrochromic devices being a two-state solid inorganic device having a high transmittance state and a low transmittance state, wherein the two or more electrochromic devices are configured to use the high transmittance state of the two or more electrochromic devices or the low transmittance state of the two or more electrochromic devices together, and wherein the first pane and the second pane are configured as a hollow glass unit having an inert gas in an interior region.

27. The multi-pane electrochromic window of claim 26, wherein the first pane and the second pane are architectural glass.

28. The multi-pane electrochromic window of claim 26, further comprising a controller configured to provide charge to the first pane and the second pane for powering the first pane and the second pane.

29. The multi-pane electrochromic window of claim 26, wherein the first electrochromic device and the second electrochromic device are located on opposite inner surfaces of the first pane and the second pane of the hollow glass unit.

30. A multi-pane electrochromic window comprising:

a first pane comprising a first electrochromic device; and

a second pane comprising a second electrochromic device;

wherein each of the first electrochromic device and the second electrochromic device comprises:

i) A tungsten oxide or doped tungsten oxide electrochromic layer, said tungsten oxide or doped oxide

The tungsten electrochromic layer has a dielectric constant of between about 30 and about 150mC/cm ² Charge between/micron

Capacity; and

ii) a counter electrode of nickel tungsten oxide selectively doped with tantalum, said nickel tungsten oxide

The counter electrode has a density of about 75 to about 200mC/cm ² Charge capacity between/microns;

wherein the ratio of the thickness of the electrochromic layer to the thickness of the counter electrode is between about 1.7:1 and about 2.3:1, and each electrochromic device is tinted to a transmittance of no less than 10%.

31. The multi-pane electrochromic window of claim 30, wherein the first electrochromic device and the second electrochromic device are all solid state inorganic.

32. The multi-pane electrochromic window of claim 31, wherein the first electrochromic device and the second electrochromic device are opposite one another in a hollow glass unit of the multi-pane electrochromic window.

33. The multi-pane electrochromic window of claim 32, wherein the first electrochromic device and the second electrochromic device are located on opposite inner surfaces of the first pane and the second pane.

34. The multi-pane electrochromic window of claim 31, wherein the first pane and the second pane are glass between 0.01mm to 10mm thick.

35. The multi-pane electrochromic window of claim 30, further comprising a controller configured to provide an electrical charge to the first pane and the second pane for powering the first pane and the second pane.

36. The multi-pane electrochromic window of claim 30, wherein:

the first pane faces to the external environment and

each of the electrochromic devices has at least a low transmission state and a high transmission state.

37. The multi-pane electrochromic window of claim 36, wherein the low transmission state of the first pane has a lower transmittance than the low transmission state of the second pane.

38. The multi-pane electrochromic window of claim 30, wherein the transmittance is in the visible spectrum.

39. A multi-pane electrochromic window comprising two or more electrochromic devices, each of the two or more electrochromic devices being located on separate panes of the multi-pane electrochromic window, and each of the two or more electrochromic devices being a two-state device having a high transmittance state and a low transmittance state, wherein the two or more electrochromic devices are configured to use the high transmittance state of the two or more electrochromic devices or the low transmittance state of the two or more electrochromic devices together at the same time, each of the two or more electrochromic devices comprising:

i) A tungsten oxide or doped tungsten oxide electrochromic layer having a thickness of between about 30 and about 150mC/cm ² Charge capacity between/microns; and

ii) a nickel tungsten oxide counter electrode selectively doped with tantalum, the nickel tungsten oxide counter electrode having a concentration of about 75 to about 200mC/cm ² Charge capacity between/microns;

40. The multi-pane electrochromic window of claim 39, wherein the first electrochromic device and the second electrochromic device are all solid state inorganic.

41. The multi-pane electrochromic window of claim 40, wherein the first electrochromic device and the second electrochromic device are opposite one another in a hollow glass unit of the multi-pane electrochromic window.

42. The multi-pane electrochromic window of claim 40, wherein the first pane and the second pane are glass between 0.01mm and 10mm thick.

43. The multi-pane electrochromic window of claim 39, further comprising a controller configured to provide charge to the first pane and the second pane for powering the first pane and the second pane.

44. The multi-pane electrochromic window of claim 41, wherein the first electrochromic device and the second electrochromic device are located on opposite interior surfaces of the first pane and the second pane.

45. A window unit, comprising:

a. a first substantially transparent substrate and a first electrochromic device disposed on the first substantially transparent substrate; and

b. a second substantially transparent substrate and a second electrochromic device disposed on the second substantially transparent substrate;

wherein the first electrochromic device and the second electrochromic device comprise a tungsten oxide or doped tungsten oxide electrochromic layer, and a nickel tungsten oxide counter electrode layer optionally doped with tantalum,

wherein the window unit is in the form of a hollow glass unit comprising a sealing barrier between the first and second substantially transparent substrates, the sealing barrier forming an insulating interior region between the first and second substantially transparent substrates, and

wherein the thermally insulated interior region contains a gas.

46. The window unit of claim 45, wherein at least one of the first electrochromic device and the second electrochromic device has an intermediate state property.

47. The window unit of claim 45, wherein the first electrochromic device and the second electrochromic device face the insulated interior area of the insulated glazing unit.

48. The window unit of claim 45, further comprising a third substantially transparent substrate to form a three pane glazing unit.

49. The window unit of claim 48, wherein the third substantially transparent substrate comprises a heatable transparent conductive oxide thereon.

50. The window unit of claim 49, wherein the heatable transparent conductive oxide layer is configured to be heated so as to facilitate a transition of the electrochromic device.

51. The window unit of claim 45, wherein the first electrochromic device faces the insulated interior area of the hollow glass unit.

52. The window unit of claim 45, further comprising a third substantially transparent substrate to form a three pane middle glass unit, wherein the second electrochromic device faces the third substantially transparent substrate and the third substantially transparent substrate includes a heatable transparent conductive oxide thereon, and wherein the heatable transparent conductive oxide faces the second electrochromic device.

53. The window unit of claim 45, wherein a ratio of the tungsten oxide or doped tungsten oxide electrochromic layer to the nickel tungsten oxide to electrode layer optionally doped with tantalum is between about 1.7:1 and about 2.3:1.

54. The window unit of claim 45, wherein each of the first electrochromic device and the second electrochromic device is tinted to a transmittance of not less than 10%.

55. A window unit, comprising:

wherein each of the first electrochromic device and the second electrochromic device comprises a tungsten oxide or doped tungsten oxide electrochromic layer and a nickel tungsten oxide counter electrode layer optionally doped with tantalum,

wherein each of the first electrochromic device and the second electrochromic device is a two-state device, and the window unit has at least four optical states, wherein the at least four optical states are:

the total transmittance is between about 60% and about 90%;

the total transmittance is between about 15% and about 30%;

the total transmittance is between about 5% and about 10%; and

the total transmittance is between about 0.1% and about 5%.

56. A hollow glass unit, comprising:

a first pane having electrochromic devices thereon; and

a transparent conductive oxide layer that is not part of the electrochromic device, the transparent conductive oxide layer configured to be resistively heated by application of electricity,

wherein the heating function of the transparent conductive oxide layer is configured to facilitate low temperature switching of the electrochromic device.

57. The insulating glass unit according to claim 56, wherein the transparent conductive oxide layer is located on the second pane.

58. The hollow glass unit of claim 56, wherein the electrochromic device is solid inorganic.

59. The insulated glazing unit of claim 57, further comprising a sealing barrier between the first pane and the second pane, the sealing barrier defining, with the first pane and the second pane, an insulated interior region of the insulated glazing unit.

60. The insulating glass unit of claim 57, wherein the second pane includes an electrochromic film thereon.

61. The insulated glass unit of claim 57, wherein the second pane includes an infrared reflective and/or infrared absorptive coating.

62. The insulated glazing unit of claim 57, wherein the second pane faces outside of the building when the second pane is installed in the building.

63. An electrochromic device, comprising:

a first transparent conductive oxide layer;

an electrochromic layer;

an ion conductor layer;

a counter electrode layer; and

a second transparent conductive oxide layer;

wherein one of the first transparent conductive oxide layer and the second transparent conductive oxide layer is configured to be resistively heated independent of operation of the electrochromic device.

64. The electrochromic device of claim 63, located on a first pane of the hollow glass unit.

65. The electrochromic device of claim 64, wherein the hollow glass unit comprises a second pane comprising an electrochromic film on the second pane.

66. The electrochromic device of claim 63, which is solid-state inorganic.

67. The electrochromic device of claim 63, wherein one of the first and second transparent conductive oxide layers configured to be resistively heated comprises indium oxide, indium tin oxide, doped indium oxide, tin dioxide, doped tin dioxide, zinc oxide, aluminum zinc oxide, doped zinc oxide, ruthenium oxide, or doped ruthenium oxide.

68. The electrochromic device of claim 63, wherein one of the first and second transparent conductive oxide layers configured to be resistively heated is a composite conductor comprising metal lines.

69. The electrochromic device of claim 68, wherein the diameter of the metal wire is about 100 μm or less.

70. An electrochromic window, comprising:

a transparent substrate; and

an electrochromic device disposed on the transparent substrate, the electrochromic device comprising a first transparent conductive oxide layer and a second transparent conductive oxide layer, wherein at least one of the first transparent conductive oxide layer and the second transparent conductive oxide layer is configured to be heated by application of electricity.

71. The electrochromic window of claim 70, wherein the electrochromic device is all solid state organic.

72. The electrochromic window of claim 70, wherein the electrochromic window is in the form of a hollow glass unit (IGU) comprising a sealing barrier between the substantially transparent substrate and another substantially transparent substrate, the sealing barrier forming an interior region between the substantially transparent substrate and the other substantially transparent substrate.